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Low tech methods of keeping a planted aquarium

An Easy Guide to CEC for the Aquarium

  By robert | January 18, 2012 - 10:31 pm | The Low Tech Plant Tank
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by Robert Paul Hudson

Lately there seems to be a renewed interest among hobbyists in using soil in freshwater planted aquariums. If you are considering doing this, one of the most basic things about soil science to take into account is CEC- cation exchange capacity. In agriculture and indoor gardening it is very important, and in the aquarium it is a factor in the overall success of using soil in a substrate.

What is CEC?

The Exchange Capacity of soil and growing mediums is a measure of its ability to hold and release various chemical elements and compounds that include nutrients for plant growth.

If you study chemistry you will learn that elements and compounds are ions, which means a charged particle. These particle ions can either be positively charged or negatively charged. Positive charged ions are called cations, and negatively charged ions are called anions.

Positive charged ions are attracted to the surface of a negatively charged medium and held there in a condensed layer where they may come into contact with plant roots. This “holding” prevents the cations from leeching out of the medium.

In agriculture a soil low in CEC would have its nutrients washed and carried away every time it rained. In the aquarium a low CEC substrate would have its nutrients leech into the water column.

Positive charged cations

Cations include some macro nutrients and all trace mineral nutrients. Other macro nutrients are anions. The most critical nutrients for CEC are Calcium, Magnesium, Potassium, Sodium, and trace minerals including iron.

Soil Organic Matter

Soil organic matter is the chief component of top soils and potting soil. This is decomposed organic material from compost, manure and humus. SOM is both positively charged and negatively charged so it will attract both cations and anions. Clay particles are almost always positively charged and attract only cations.

Cation Exchange Capacity is the measure of how many negatively charged sites are available in the soil or medium. Clay and other inert materials will continue their CEC indefinitely while SOM will last only until the organic material breaks down from further decomposition.

Cations and Anions

Common Cations: (ions grouped by charge)

Name Formula Other name(s)
Aluminum Al+3
Ammonium NH4+
Barium Ba+2
Calcium Ca+2
Chromium(II) Cr+2 Chromous
Chromium(III) Cr+3 Chromic
Copper(I) Cu+ Cuprous
Copper(II) Cu+2 Cupric
Iron(II) Fe+2 Ferrous
Iron(III) Fe+3 Ferric
Hydrogen H+
Hydronium H3O+
Lead(II) Pb+2
Lithium Li+
Magnesium Mg+2
Manganese(II) Mn+2 Manganous
Manganese(III) Mn+3 Manganic
Mercury(I) Hg2+2 Mercurous
Mercury(II) Hg+2 Mercuric
Nitronium NO2+
Potassium K+
Silver Ag+
Sodium Na+
Strontium Sr+2
Tin(II) Sn+2 Stannous
Tin(IV) Sn+4 Stannic
Zinc Zn+2

Common Anions: (ions grouped by charge)  (anions grouped by periodic position)

Simple ions:
Hydride H- Oxide O2-
Fluoride F- Sulfide S2-
Chloride Cl- Nitride N3-
Bromide Br-
Iodide I-
Oxoanions:
Arsenate AsO43- Phosphate PO43-
Arsenite AsO33- Hydrogen phosphate HPO42-
Dihydrogen phosphate H2PO4-
Sulfate SO42- Nitrate NO3-
Hydrogen sulfate HSO4- Nitrite NO2-
Thiosulfate S2O32-
Sulfite SO32-
Perchlorate ClO4- Iodate IO3-
Chlorate ClO3- Bromate BrO3-
Chlorite ClO2-
Hypochlorite OCl- Hypobromite OBr-
Carbonate CO32- Chromate CrO42-
Hydrogen carbonate
or Bicarbonate		 HCO3- Dichromate Cr2O72-
Anions from Organic Acids:
Acetate CH3COO- formate HCOO-
Others:
Cyanide CN- Amide NH2-
Cyanate OCN- Peroxide O22-
Thiocyanate SCN- Oxalate C2O42-
Hydroxide OH- Permanganate MnO4-

Calcium/Magnesium ratio

The Calcium to Magnesium ratio determines how tight or loose a soil is. The higher the Calcium the looser it is and the higher the Magnesium, the tighter it is. A high Calcium soil will have more oxygen and support more aerobic breakdown of organic material, a high Magnesium soil will be more likely to have organic material ferment. If you have an extreme level of Calcium,  the soil will loose its beneficial granulation and structure, which will interfere with the availability of other nutrients to plant uptake.

How plants get the nutrient cations 

The roots and microorganisms get these nutrients by exchanging free hydrogen ions.  The free hydrogen H+ fills the (-) site and allows the cation nutrient to be absorbed by the root or microorganism.

How to Increase CEC

Organic materials in soil usually have high CEC surfaces. This includes compost, peat, manure, and humus. Clays and other inert materials may also have high CEC surface areas and can be mixed with soil. Fired clay particles have much higher CEC than raw clay. This is what clay gravel aquarium substrates consist of. There are many different types of mineral clay and some are actually very low in CEC.

Here are some high CEC mediums that could be mixed with soil:

Cation Exchange Capacities for various growing media amendments and selected media.
Material/Cation Exchange Capacity meq/100g
Perlite/ 1.5 – 3.5
Silt/ 3.0 – 7.0
Clays/ 22.0 – 63.0
Pine Bark/ 53.0
Vermiculite/ 82.0 – 150.0
Sphagnum Peat/ 100.0 – 180.0
Humus/ 200.0
Peat moss : vermiculite 1:1/ 141.0
Peat moss : sand 1:1/ 8.0
Peat moss : perlite 1:3/ 11.0
Peat moss : perlite 2:1/ 24.0

Sources: see Bunt, A.C. 1988, and Landis, T. D. 1990.

The following is word for word from a University web site I saved several years ago. I have since lost the link:

Container growing mediums:

Sphagnum peat moss
Sphagnum peat moss, derived from the genus Sphagnum, contains at least 90% organic matter on a dry weight basis. In addition, this peat moss contains a minimum of 75% Sphagnum fiber, consisting of recognizable cells of leaves and stems.

Approximately 25 species of Sphagnum exist in Alberta, Canada and 335 species are present throughout the world. Sphagnum fuscum is an important species bearing many desirable traits. Sphagnum grows in northern cool regions and is also located in peat bogs found in Washington, Maine, Minnesota, and Michigan.

Many pores are present in the leaves of sphagnum; when used as growing media, as much as 93% of the water occupying this internal pore space is available for plant uptake (Peck, 1984). After draining, sphagnum peat can hold 59% water and 25% air by volume.

Sphagnum is usually characterized by an acidic pH, low soluble salts content, structural integrity, and the ability to serve as a nutrient reserve (Landis, 1990).

Although peat mosses are classified into four different groups, variation may exist within any one type of peat moss. Peats of the same classification often differ notably in quality, and even peats from the same bog taken from separate layers can possess different chemical and physical properties.

Sphagnum peat moss is classified as light or dark peat, based on its color. Light peats are characterized by a large amount of internal pore space, 15-40% of the pore space comprises aeration porosity. Dark sphagnum peat does not display the elasticity of light peat and is usually not as long lasting. Dark sphagnum peat moss maintains twice the cation exchange capacity of light peats, yet does not possess as much total or aeration porosity.

Inorganic media
Materials such as vermiculite, perlite, and sand represent the inorganic fraction often used in container media formulations. These materials generally increase the aeration porosity and drainage yet decrease the water-holding porosity of media. Inorganic components are usually inert materials characterized by a low cation exchange capacity.

Vermiculite
Vermiculite is a commonly used inorganic media component which is mined in the U.S. and Africa. This mineral, comprised of an aluminum/iron/magnesium/silicate mixture, is excavated as a material composed of thin layers. Processing includes heating the vermiculite to temperatures upwards of 1000 degrees C, which converts water trapped between the layers of the material into steam. The production of steam results in a pressure that expands the material, increasing the volume of the pieces 15 to 20 times their original size.

Vermiculite is sterile because of these high heating temperatures used during processing. Vermiculite is characterized by a high water-holding capacity as a result of its large surface area: volume ratio, a low bulk density, nearly neutral pH, and a high cation exchange capacity attributed to its structure. Because it compacts readily when combined with heavier materials, vermiculite is sometimes recommended more for propagating material than container media.

Vermiculite gradually releases nutrients for plant absorption; on average it contains 5-8% available potassium and 9-12% magnesium. This inorganic media component can adsorb phosphate – some of which remains in an available form for plant uptake – but cannot adsorb nitrate, chloride, or sulfate. Vermiculite can fix ammonium into a form that is not readily available for plant absorption. This fixed nitrogen is gradually transformed to nitrate by micro-organisms, making it available for plant uptake.

Vermiculite is manufactured in four different grades, differentiated by particle size. Insulation grade vermiculite and that which is marketed for poultry litter (which has not been treated with water repellents) has been used with some success. Vermiculite which has been treated with water repellent, such as block fill should not be used as growing media. Because vermiculite tends to compact over time, it should be incorporated with other materials such as peat or perlite to maintain sufficient porosity. It should not be used in conjunction with sand or as the sole media component, because as the internal structure of vermiculite deteriorates, air porosity and drainage decreases (Landis, 1990).

The particle size of vermiculite influences the water-holding and aeration porosity of the material. Although grade classification is based upon particle size, each grade is represented by a range of particle sizes. Note that grades consisting of larger particle sizes have a higher aeration porosity and lower water-holding porosity than grades consisting of a smaller range of particle sizes. Properties of the four vermiculite grades are shown in an associated table.

Perlite
A mineral of volcanic derivation, perlite is a second inorganic component which may be used in formulating container mixes. This chemically inert material is extracted in New Zealand, the U.S., and other countries and is usually mined by scraping the earth’s surface. The processing method includes a grinding and heat treatment (up to 1000 degrees C) which results in very lightweight, white sterile fragments. As the ore is heated, internal water escapes as steam, resulting in the expansion of the material.

Perlite has a very low cation exchange capacity, low water-holding capacity (19%), and neutral pH. The closed-cell composition of perlite contributes to its compaction resistance, enhances media drainage, and heightens the aeration porosity of peat-based media (Bilderback 1982). Because perlite contains only minute amounts of plant nutrients, liquid feeding is a practical mode of fertilization. Be aware of possible aluminum toxicity in acidic media (pH < 5).

The very low levels of fluoride perlite contains is not likely to pose plant health problems. Any soluble fluoride present in a media characterized by 6.0 < pH < 6.5 will precipitate out of the media with excess calcium from sources such as gypsum, limestone, or calcium nitrate.

Although perlite has several positive attributes, it also has drawbacks. Perlite consists of many fine fragments which, when dry, can lead to lung or eye irritation. In addition, because water clings to the surface of perlite, it may tend to float in the presence of water (Landis, 1990).

Perlite contains, on average, 47.5% oxygen, 33.8% silicon, 7.2% aluminum, 3.5% potassium, 3.4% sodium, 3.0% bound water, 0.6% iron and calcium, and 0.2% magnesium and trace elements (Perlite Institute, 1983). Although a uniform categorization of perlite does not exist, individual producers of this inorganic component assign grade levels. This inorganic media amendment is sometimes recommended for use only in propagation media because of its low bulk density and tendency to compact.

In comparison with sand, polystyrene, or pumice, perlite has the greatest inner total porosity. Coarse perlite is characterized by approximately 70% total porosity, 60% of which is aeration porosity. Perlite can retain two to four times its dry weight in water, which is much greater than that of sand and polystyrene, yet much less than the water-holding capacity of peat and vermiculite (Moore, 1987).

Sand
Sand has been used as an inorganic media component to add ballast to containers. Some sands contain calcium carbonate which may raise media pH undesirably. A rise in pH may lead to nutrient deficiencies, particularly of minor elements such as iron and boron. A few drops of dilute hydrochloric acid or strong vinegar may be added to sand to test for carbonates; if bubbling and fizzing result, carbonate is present as a result of carbon dioxide production.

Sand used for container media should have a 6 < pH < 7. Sand maintains good drainage, a low water-holding capacity, and a high bulk density when used independently of other materials. Because of its shape and size, sand can obstruct pore spaces, decreasing drainage and aeration, instead of improving porosity.

Various sand particle sizes have been recommended for container media use, including ranges of 2-3 mm or 0.05 – 0.5 mm (fine sand) in size (Landis, 1990). In addition, another recommendation suggests that 60% of the particles be within 0.25-1.0 mm range, and 97% be greater than 0.1 mm and less than 2 mm (Swanson, 1989). Uniformity coefficients assigned to sand mixtures signify the amount of sand which is within a certain size range; a coefficient < 4 is evidence of a homogeneous sand mixture (Swanson, 1989). If the correct grade of sand is used, the wet ability of the media is enhanced.

Calcined clays
When fired at high temperatures, some clays, fuel ash, and shales form stable compounds that possess low bulk densities and internal porosities of 40-50%. Though calcined clays alter the physical attributes of media in a positive way, they also decrease the level of water-soluble phosphorus in the mix.

Because calcined clays are characterized by a high cation exchange capacity, fertilizer application rates may need to be modified if calcined aggregates are incorporated into the media mixes (Bunt, 1988).

Pumice
Pumice is produced as volcanic lava cools; escaping steam and gas contribute to its porous nature. This alumino-silicate material contains potassium, sodium, magnesium, calcium, and slight amounts of iron. Pumice can absorb K, Mg, P, and Ca from the soil solution and render it available for plant absorption later (Bunt, 1988).

Zeolite

Zeolite is a natural as well as synthetic mineral that has a honeycomb structure that provides a high CEC. It is inert, and in gravel form is suitable for the aquarium.

 

Conclusion

1. Top soil, potting soil is generally high in CEC, but has a limited life

2. Clay, depending on the type may be high in CEC and lasts forever

3.  Perlite and Vermiculite float in water so are not suitable for the aquarium

4.  Sand has low to zero CEC

Further reading:

Jamie Johnsons CEC and nutrient analysis

http://home.infinet.net/teban/jamie.htm

January 28th, 2012, Aqua Botanic Radio will be talking about soil in the aquarium

http://www.blogtalkradio.com/aquabotanic

 

Adding Carbon without C02

  By robert | September 5, 2011 - 12:45 pm | Aquarium Plants, The Low Tech Plant Tank
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by Robert Paul Hudson

I recently spoke with Dr. Greg Morin, CEO of Seachem Labs about their  product Flourish Excel…

>. How does Excel add carbon to the water?
As a simple, low molecular weight organic compound.

> Can you please define photosynthetic intermediates and explain the process?
Photosynthetic intermediates includes compounds such as ribulose
1,5-bisphosphate, 3-phosphogylcerate, 2-carboxy-3-keto-D-arabinitol
1,5 bisphosphate. Although the names are complicated, the structures
are quite simple (3, 5, & 6 carbon chains). Flourish Excel does not
contain these specific compounds per se, but one that is quite
similar. It is in its structural similarity that Flourish Excel is
able to be utilized in the carbon chain building process of
photosynthesis. Simple chemical or enzymatic steps can easily convert
it to any one of the above named compounds (or a variety of others).

> Does this affect the pH as CO2 gas does?
No, it does not affect pH.

>Does Excel’s added carbon work enough to provide plants what they 
need without the need of CO2 injection?
That depends on your definition of need ;-) We have been using the
product here for several years (during the testing phase) and all of
our planted tanks have been doing extraordinarily well. We do not use
any CO2 injection. We usually have to cut and trim every few weeks or
so. However, if your goal is to have the kind of growth where you
would need to cut and trim weekly (because the plants grow out of the
tank every week) then you’re not going to see that with Flourish
Excel as the sole carbon source. But using Flourish Excel as the sole
source of carbon is certainly not going to leave the plants lacking
for carbon by any stretch.

> Does Excel offer additional benefits to a planted tank?
It helps to maintain iron in the ferrous (Fe+2) state which is more
easily utilized by the plants.

>. Are there any enviornmental factors in the tank that either 
impede or increase Excel’s effectivness?
The use of a skimmer will tend to remove it, especially if the tank
is somewhat “dirty” (i.e. hazy looking, lots of detritus floating
around etc).

> Can algae feed on Excel?
No. I’m sure this may raise a few eyebrows ;-) since at face value
this would be a reasonable expectation. But, for reasons Uncle Sam
won’t let us discuss, all I can say is that algae can’t feed on Excel
and I will leave it as an exercise to the reader to deduce why this
is the case (big picture folks, no chemistry involved ;-) .

Gregory Morin, Ph.D.
Seachem Laboratories, Inc.      www.seachem.com     888-SEACHEM

What soil to use in low tech plant tanks

  By robert | August 28, 2011 - 4:25 pm | The Low Tech Plant Tank
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by Robert Paul Hudson

Soil in the aquarium has become more popular again in recent years as a low tech approach that often includes the use of minimal lighting and no added C02. Diana Walstad wrote a book called Ecology of the Planted Aquarium around this method.

Soil is used to provide either macro nutrients or trace minerals, or both.  Nitrogen is the chief macro nutrient and is provided in the form of nitrate or ammonia.  Nitrogen is derived from decomposing organic matter, which in soil is a combination of leaf compost and manure. Mineral elements come from decomposed rock. Top soil contains high amounts of organic material while sub soil has higher concentrations of minerals and sand. Garden top soil often also contains sticks and bark, while subsoil is usually pretty clean. “Potting” soil is simply garden top soil without the sticks and often has fertilizer and Perlite added.  Perlite is beads of white foam like material that break up the soil allowing exchange of oxygen and also absorbs nutrients. How beneficial they are in the aquarium is uncertain, but they float in water.

Which is better sub soil or top soil?
Top soil has been avoided in many circles for fear of what large amounts of decaying organic material will do in the aquarium. There are two main areas of concern: algae control and anaerobic substrate. Soil heavy in organics may release large amounts of ammonia into the water, which certainly could cause an outbreak of algae and have an adverse affect on the fish and animal population temporarily until it is under control. A more long term problem is anaerobic areas of the substrate. As organic material breaks down and decays, the process depletes oxygen that is surrounding the material and eventually creates methane gas. Lack of oxygen creates dead spots in the substrate, plant roots in the anaerobic areas will turn black, and if the plant’s roots cannot reach outside the affected area to draw oxygen, the whole plant may die.

The Ideal Compromise

Because of the potential anaerobic problems, for many years people focused on using sub soil, “sandy loam”. Because of being very low in organic material, it was considered much safer and it primarily offered minerals. Clay was also used for the same reason. Laterite or clay additives are used as a thin layer in the bottom of the substrate to provide minerals. Later companies developed clay gravels for the same purpose: a substrate medium that was inert, provided an endless supply of oxidized minerals, and had good cation exchange capacity, (ability to absorb nutrients from the water.) Diana Walstad’s book and others put forth the benefit of having organics in the substrate in small controlled amounts and people began considering top soils again.

Ideally, the best of both worlds would be a top soil that is finely pulverized without any leafy chunks or fresh manure. It should also be free of any fertilizer additives. Twigs and bark should be screened out. They do NOT decompose in the substrate. They are just small pieces of wood. Does wood decompose in your tank? Not really.

Brands of top soil vary across the country, and even the same brand can vary in content depending on where it was processed. If you cannot get a sample from the bag before buying it, go to a nursery and describe to them the type of soil you want: a mix of top and sub soil without any chunks of leaf, bark, twigs, or manure, and they may be able to bag something just for you.

Suggestions from my friend Jane:

Perlite – while not a bad thing for houseplant soil, this stuff “lightens” heavy soils, especially those that tend to be high in clay. It provides porosity and helps to allow container plants’ roots access to air from the small spaces between particles (very important for terrestrials). For the aquarium keeper, this stuff floats, and is a royal pain in the @$$, as the little white bits will float up for months and cling to anything in the water surface.

Vermiculite – also generally a good ingredient in houseplant soil, this is a mineral that has been expanded by exposing it to great heat. While it also “lightens” soils to some extent, it also provides a lot of surface area for water to cling to, and helps absorb and retain water, while not staying thoroughly WET. It evens out the wet/dry cycle. For the aquarium keeper, this isn’t as annoying a floating component as perlite, and may help against compaction. (*aside – I’ve actually added some vermiculite to a soil underlayer as an experiment, with very good results to date).

Wetting Agents. These are surfactants. I’ve personally had a very bad experience with these when trying to pot up some very rare terrestrial plant cuttings. My bad experience was with Martha Stewart’s potting soil from KMart. Shredded sphagnum peat has an annoying habit of being difficult to wet once it gets very dry. It actually repels water to some extent. A wetting agent, or surfactant, gets the water to make contact with the other materials, and increases absorbability. But, it also increases the moisture retaining time. For me, this kept the precious cuttings too wet for too long, and caused rot. I’m not positive what the effect would be in an aquarium, but my sense is that it would not be good for the creature or plants. Plants have a very thin natural cuticle to protect them, and I’d guess this would not “play nicely” with that. Who knows what the long term effects on fish would be.

Take a look at some of the cheaper soils. Those tend to NOT have wetting agents, fertilizers or other questionable amendments. I’ve used “Hyponex” and “Jolly Gardener” but found the contents of both brands to vary widely depending on where the bag was purchased, and at what time of year. Try a small bag of a few different types. Anything you don’t use in the aquarium would probably be fine for houseplants.

Here is a VERY general assessment technique: Moisten it, play with it. When moderately moist (like a wrung out sponge), a small handful should have a bit of give when you squeeze it in your fist. Now open your hand flat. Does it crumble apart? That indicates its high in sand. Does it stay compressed, like a hard lump? High in clay. Does it look shiny or slick, or very muddy? That indicates a lot of organics.

Ideally, it will fluff back out a little bit (like when baking a cake – touch the top to see if its done – it should sping back when lightly touched) as you’ve released the compression. It should generally keep its shape, perhaps fracturing in one or two places. If you push on it, it should then break apart rather easily.

Now smell it. It should not smell moldy or astringent or bitter. It should smell pleasantly earthy, and the smell should not be noticable unless you have your nose right up to it.  Thanks Jane! 

 

Preparing the soil

You do not need to soak or wash the soil. All you will accomplish is making a mess. You can however sift out any twigs or bark. Use a wire mesh or screen strainer. If you spread out the soil and let it sit under the sun for a few hours, (12 hours), until the soil is completely dry, that will neutralize excess ammonia. Another trend currently is “mineralizing” the soil with powdered minerals. The advantage of this is the minerals in the soil would then be immediately available to the plants from day one instead of having to first bind with organic acids to become water soluble. It is a messy, time consuming process that I am not convinced is worth the effort. You can read about it here: http://gwapa.org/wordpress/articles/mineralized-soil-substrate/

Diana Walstad

Moderation is the key

The key to success is to use any kind of soil in moderation.  Anaerobic conditions are most dangerous when in large amounts. Isolated anaerobic spots are normal in any aquarium and are not too much of a concern. In a healthy, growing aquarium the release of nitrogen into the water is of no concern and does not mean an algae outbreak will be the end result unless it is a significantly large amount that the tank ecosystem cannot handle. Diana Walstad states: “I use about 1 gal of soil/sq. foot for a 1″ layer of moist soil.” She also goes on to say that soil should be covered with no more than an inch of gravel.  She explains the reason is that the deeper the soil is in the substrate, the harder it is for oxygen to reach it and the area will become severely anaerobic.  The only problem I have with that is the fact an mere inch deep covering can be easily uncovered every time you move a plant, want to re-arrange ANYTHING, or do anything to disturb the gravel. I would go a little deeper.

 

 

 

 

 

 

 

 

 

Preparation and Maintenance of a Planted Aquarium With a Nutrient Rich Substrate

  By robert | August 28, 2011 - 10:38 am | Aquarium Plants, The Low Tech Plant Tank
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Preparation and Maintenance of a Planted Aquarium With a Nutrient Rich Substrate

Article  and photos by Dusko Bojic

Step 1 – The preparation of the substrate/soils

Since plants grow much better in nutrient rich substrates ideally soils should be used. (E.g. potting soils, commercially available aquarium soils)
Soils also support various beneficial bacteria (chemoautotrophic, heterotrophic) which are involved in the decomposition of organic compounds, nitrification/de-nitrification, reduction and oxidation of heavy metals and gasses into plant nutrients. This means that using plain sand or gravel would be a poor choice for establishing a proper environment for aquatic plants especially in Low-light Low-tech aquariums.

Click on the ilustration to enlarge it


In aquariums the soil should be approximately 4cm (1.5 inch) deep and covered with 4cm of sand or gravel which is 0.5-2mm in size.

There is another thing that should be considered before covering the soil with gravel. Not all tap water is the same. In the case your tap water is on the soft side (low levels/concentrations of Calcium, Magnesium and Bicarbonates) mix some crushed Dolomite or Calcium carbonate with the soil.
Ca/Mg Carbonates will prevent the acidification of the aquatic ecosystem and will provide the plants with Ca and Mg. Bacterial activity slows down under very acidic conditions (pH3-pH5) and by adding Dolomite the carbonates will create a buffering capacity.
Also metal oxides will become way too soluble when exposed to very low soil pH causing metal toxicity to plants (iron, aluminium).
In the case your tap water is hard there is no need for mixing Dolomite with the soil.

Water hardness:
4-8 GH is soft
8-12 GH is medium hard
12-18 GH is fairly hard
18-30 GH is hard
Most plants prefer water hardness of 6-10 dGH.

NOTE!!! When suggesting the use of nutrient rich substrates I don’t mean Fluorite or commercially available substrates which are mostly rich in Iron (Fe). I suggest the use of soils which provide most of the macro and micro nutrients required for healthy plant growth.
E.g. the potting soil I use in some of my tanks is very rich in nutrients.
It contains N, P, K, Mg, S, Ca, Fe, Mn, B, Cu, Zn, Mo.


Once the soil is covered with sand or gravel add de-chlorinated water to the tank. NOTE! Add just enough water to saturate the substrate.
The tank should not be submerged yet!!
This part is very important!

Potting soil (or commercial aquarium soil) is terrestrial (exposed to O2) and has to go through a very sudden change. Once saturated in water O2 levels decrease rapidly used up by the bacteria.
Bacteria use O2 during organic decomposition. At the start the soil once submerged will release lots of nutrients into the water column.
The soil has to settle down before flooding the tank. With this method we can avoid unnecessary algae blooms and water turbidity.
Keep the soil saturated for 1to2 month. Note! Do not flood the aquarium yet. Add more water if it evaporates because the soil must remain submerged at all times to convert (soil cycling) into a settled aquatic soil which the plants require. It is important to wait to ensure sufficient bacteria development involved in nitrification of Ammonium to Nitrates, avoiding NH4/NO2 spikes which are very toxic to fish and crustaceans.

For those of you planning to use CO2 this is the perfect time to start planting. Many plants can grow emerged if substrate is saturated in water and humidity is kept high.
To keep the humid environment; seal the tank (some air can be allowed to enter of course).

Suitable plants for such emerged method are:
Hemianthus calitrichoides Cuba, Glossostigma, Marsilea sp., Eleocharis grass, Cryptocoryne sp., Microsorum, Anubias sp., and even Java/Christmas Moss.
This method also known as the “Dry Start Method” by Tom Barr is best suited for creating a foreground carpet. E.g. Hemianthus Cuba (HC) needs 4-8 weeks to fully cover the foreground.
Keep lights on for 12 hours to encourage plant growth.

This planting method doesn’t suit Low-Light Low-Tech aquariums because the plants are exposed to atmospheric CO2 during the emerged stage. Once flooded the CO2 is cut off almost immediately
and plants will start melting in a matter of days. (e.g. Cryptocoryne sp). And for this particular reason this emerged planting method suits CO2 injected aquariums (High-Tech) perfectly.

Once the plants are submerged they get all the CO2 via the pressurised CO2 system (25-30ppm) and no melting will occur.
I presume that aquariums where Excel or Easy Carbo (instead of the CO2 gas) will be dosed can also try this “Dry Start” planting method.

Photo 1 – day one of the emerged method (HC)
Photo 2 – eight weeks later

After approximately 2 months it is really worthwhile waiting, the tank can be flooded. Once the aquarium is filled with water, flush it out!
We do this because the nutrients which diffuse out of the soil into the water column might cause unnecessary algae blooms.

If you are extra cautious you can repeat the flush-out a few times. There is no harm in doing this but the water must be dechlorinated before adding it to the tank.
NOTE; never add ice cold tap water back into the system. It should be tepid to start with. Set the heater to approximately 26’Celsius.
At this stage introduce all the plants you want to grow. It is best to plant heavily from the submerged start. Also it is good to plant lots of rooting plants. Plant roots will add Oxygen into the rhizosphere to protect themselves from heavy metal toxicity and also by doing this the O2 enables the oxidation of the very toxic Hydrogen Sulfide gas (H2S) converting it to harmless salt HSO4 and the oxidation of Methane gas to CO2 and water. The plant roots will prevent soil Redox from becoming too low.


Step 2 – Water Circulation and Surface Agitation

It is of great importance to create sufficient water circulation and surface agitation in a planted Ecosystem.

Circulation will evenly distribute nutrients making them available for plants and bacteria. Aim for a circulation between 5-8 x of the tank volume per hour depending on plants grown and fish kept. Some prefer stronger currents while others weaker ones. Some aquatic gardeners use circulation of up to 10 x the tank volume per hour but they do reduce the water flow by using very long submerged spray bars which should be placed just below the surface.

Surface Agitation will insure sufficient gas exchange and will prevent the surface film from forming. Even though plants will provide lots of O2 through photosynthesis especially in CO2 injected systems it can’t hurt to add extra O2 via the surface agitation.
One should bear in mind that Oxygen is one of the most important electron acceptors involved in animal and bacterial metabolism.


At higher temperatures O2 levels decrease especially during the summer. When the temperature gets higher it is beneficial to create a strong surface agitation or add another power head for this purpose only. I have found that it is not the temperature that affects the fish/shrimp/plants during summer months but rather the low O2 levels. At higher temperatures the bacterial metabolism accelerates and uses up lots of O2 for nutrient recycling.

E.g. I live on the top floor and during the summer time the temperature of my tanks do go up to 31’Celsius. In the past I believed that this would harm fish, shrimps and plants. Now I know better. What I do under such extreme conditions is that I create a very strong (but no splashes) surface agitation in all my aquariums for good gas
exchange and I never experience any problems with fish/crustaceans or plants.
In planted aquariums keeping good Oxygen levels is as important as keeping good CO2 levels.

Step 3 – Finding the balance between lights, CO2 and nutrients

Because of people like Tom Barr, Greg Watson and Diana Walstad aquatic plant growing isn’t that difficult anymore.
Thanks to them aquatic gardeners have a better understanding about plant requirements and because of that we are able to grow healthy plants without deficiency symptoms and/or algae blooms.

For healthy growth plants require Carbon (C), Oxygen (O), Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg) and Sulphur (S) as the Macro Nutrients and Iron (Fe), Manganese (Mn), Zink (Zn), Copper (Cu), Boron (B), Nickel (Ni), Chlorine (Cl) and Molybdenum (Mo) as the Micro Nutrients.
In comparison to the Micro-nutrients plants require larger amounts of Macro-nutrients.
Macros and Micros can be added via commercially available products like Tropica’s AquaCare Plant Nutrition N&P+traces and Seachem’s Flourish macro and micro fertilisers as well as dry fertilisers like KNO3, KH2PO4, Epsom salts, etc…

It is all about finding the right balance between the lights, CO2 and nutrients.
I have to draw a line here! There is a difference between dosing nutrients to an aquarium with only a few plants and heavily planted aquarium.
Plant density and plant growing rate is something to consider before deciding on the nutrient dosing methods.

Remember that there is a huge difference between dosing and over-dosing with nutrients. Dosing strategies are generally suggested for use in heavily planted aquariums were nutrient uptake is high!!!

Everything starts with the light. One can decide between using Low lights, Medium or High lights over the aquarium.
The light strength affects the plant growing rate. The stronger the light the faster the plant will grow and the faster it will up take the nutrients.
Deciding which light levels to use depends entirely on the aquatic gardener’s life style and goals.

Planted aquariums are complex and dynamic ecosystems, which hugely depend on us (the aquarist).
Nature doesn’t have much influence on them, and for that reason we are the ones pulling all the strings in leading them to an algae free/thriving planted ecosystem.

Plants need stable nutrient levels to thrive and grow lush. It is up to
the aquarist to understand the planted aquarium ecology and influence this system by finding the right nutrient balance.

Aquarium plants can be successfully grown in several ways and most of it depends on the light. This is simple mathematics;
The stronger the light, the faster the plant will grow, and the nutrient uptake will be greater.

Less light = slow growth = slow nutrient up-take.

Aquarium light levels:

Low lights are between 1 – 2 watts per gallon (0.3 – 0.5 watt/litre)
Medium lights are between 2 – 3 watts per gallon (0.5 – 0.8 w/l)
High lights have 3 watts per gallon or higher (0.8 w/l or higher)

How to calculate the light level:

Divide the total aquarium light wattage with the aquarium volume (gallons or litres) to get the light level per gallon/litre.

e.g. Lets say the aquarium is 48 gallons (180 litres) and has 2 x 30 watt fluorescent tubes.
2×30 watt = 60 watts in total over the aquarium
60 watts divided by 48 galls = 1.25 w/g, or
60 watts divided by 180 litres = 0.33 w/l
meaning this is a low-light set-up.

Common planted aquarium methods are:

Low-light Low-tech

Low-light (non-CO2 injected) planted aquariums, where soils are used as the plants’ main nutrient source. This is a low maintenance method, which requires very few water changes.

Low-light High-tech

Low-Light planted aquariums where CO2 is used to stimulate the plant growth. This system will depend on extra fertilising and often water changes to stay in balance

High-light High-tech

High-light planted aquariums were CO2 is injected to stimulate the plant growth. Higher light levels provide plants with a huge amount of energy promoting luxurious lush plant growth. This is the common method used for creating stunning looking aquascapes; (Aquascaping Competitions)

Which method suits me best? you might ask

This depends on your goals and your life style.

1. Lets say you have a very busy life; long working hours, studying, kids, etc… and don’t have much time left for often aquarium water changes.
In this case, it is best to choose the Low-light Low-tech planted method, which needs only 5-6 water changes per year. For Low-tech tanks I dose nutrients once a week e.g. Tropica Plant Nutrition+ (read
plus) which contains NPK and traces 5ml per 50 litres. Even though plants can get most of the nutrients via soils we have to bear in mind that soils will become exhausted after approximately 6-12 month. To prevent this from happening it is beneficial to dose macro and micro nutrients via dry or liquid fertilisers once a week.

2. You have a tight budget, but would like to create a nice looking aquascape. Choose the Low-light High-tech method, meaning less light, less nutrients, inexpensive DIY/Yeast CO2 solutions, etc…
For this method I dose Tropica Plant Nutrient N & P + traces 1-2 times a week followed by a weekly 50% water change.

3. Or, your goal is to create a stunning looking planted tank for an Aquascaping Competition. In this case High-light High-tech method would be the best option. But to succeed in creating such a system, one has to dose nutrients often and do large weekly water changes to prevent nutrient over-dose. The best nutrient dosing strategy is known as the EI (Estimative Index) which was invented and popularized by Tom Barr.

For my 160 litres High-tech heavily planted aquarium with up to 0, 8 watts per litre I dose as followed:

*CO2 approximately 4 bubbles per second monitored via Drop Checker (25-30ppm).

Tuesday – (after the 50% water change) 1/2 teaspoon of KNO3, 1/8 teaspoon of KH2PO4 and 1/2 teaspoon of GH-Booster.

Wednesday – 10ml of Tropica Plant Nutrition for traces

Thursday – 1/2 teaspoon of KNO3, 1/8 teaspoon of KH2PO4

Friday – 10ml of Tropica Plant Nutrition for traces

Saturday – 1/2 teaspoon of KNO3, 1/16 teaspoon of KH2PO4

Sunday – 10ml of Tropica Plant Nutrition for traces

Monday – I dose nothing

With Tuesday it starts from the beginning (50% water change and nutrient re-dosing as followed above).

NOTE: Just remember, unbalanced planted tanks will lead to algae bloom, so e.g. choosing the High-light method, but not performing often water changes/plant pruning/nutrient dosing will lead to algae heaven.

Carbonate Hardness (KH) should never be under 4KH. Carbonates and Bicarbonates have the acid binding capacity. Carbonate Hardness level which is under 3KH doesn’t have a very good buffering capacity and therefore pH might shift drastically. If necessary dose Bicarbonates (Baking soda) to increase the KH.

Most plants can grow under all 3 light conditions if CO2 is not the limiting factor. For example it is believed that Hemianthus calitrichoides Cuba (HC) needs high lights to be able to grow into a foreground carpet. This isn’t true! This plant will do just fine under lower light conditions as soon as the CO2 is not a limiting nutrient. In CO2 limited systems HC like many other plants will grow upwards trying to reach over the water surface where the atmospheric CO2 is available. Many believe that plants grow towards the surface to get closer to the light source which isn’t true.
The most common reason behind plants growing like this or simply melting away is due to the limiting CO2 factor.
Of course under low lights plants will grow slower but with good CO2 levels they will eventually grow into the desired aqua-scape.


Step 4 – Aquarium Hygiene and Plant Maintenance

Once the aquarium is maturing organic matter starts accumulating creating mulm, filters get clogged with particles, and plant bio mass increases to the point where tank maintenance becomes necessary.

With each water change it is good to perform light substrate vacuuming just over the gravel. No need for deep vacuuming in planted aquariums with many rooted plants. Like this we keep the beneficial Oxidizing Microzone (top layer of substrates) from becoming anaerobic (clogged with mulm).
The Oxidizing Microzone helps to convert toxic NH4 to NO3 and it keeps nutrients trapped in the substrate (oxidation).

Filtration will remove floating particles and help in nutrient recycling. External filters seem to work best in planted aquariums. One of the reasons they are a better choice than inner filters is that they keep all the collected dirt outside of the tank. Once the filter is opened for cleaning, all the dirt stays in it. On the other hand when taking the inner filter out of the tank for maintenance half of the trapped dirt leaks straight back into the aquarium. This should be avoided and for that reason external canister filters and hang on back filters (HOB) should be used.

Clogged filters will reduce circulation. Clean them regularly. How often depends on the pump type (external, inner) and fish bio-load.
When cleaning the filters make sure not to rinse them under tap water which contains chloramine. Such tap water can damage the beneficial bacteria living in the filter. Always rinse in aquarium water from the water change.


Under balanced nutrient conditions plants will grow better especially the fast growing stem plants. One should never allow them to grow to the surface. When this happen gas exchange becomes limited and low Oxygen levels might occur causing various issues e.g. algae, surface film, NH4/NO2 accumulation, stressed fish, etc…
Also, overgrown plants will reduce water circulation creating dead zones.Prune the plants regularly. This will not only encourage new growth but will make your plants look much better. The more you prune them the bushier they become.
Foreground plants should be mowed regularly. They tend to grow on top of each other creating a tick carpet. If the carpet is allowed to grow too tick it will start to rot from the underside and the whole carpet might float up (e.g. HC).

Partial water change is very important and should be performed weekly in Hi-tech and “Excel Only” aquariums. Like this we reduce excess nutrients which might have built up via extra fertilisation.
Hi-tech systems require frequent nutrient dosing (3x a week) and for that reason it is beneficial to do weekly water changes (50%) to re-set the system.
Low-tech aquariums require less water changes to prevent CO2 fluctuations. These systems need steady CO2 levels in accordance to avoid algae issues. Tap water is rich in CO2 and with each WC we add a fair amount of CO2 which plants will consume in just a day or two leaving them with low CO2 levels for the rest of the week. Fluctuating CO2 levels will very likely cause algae issues (stressed plants). For Low-tech tanks it is enough to do a 50% water change every 2 month. For that reason we rather under-stock with fish to minimize the organic build up.


Certain fish and crustaceans can also help a lot in maintaining hygiene in a planted aquarium.

One of my favourite is the Caridina multidentata shrimp (formerly C. japonica) which was popularized by Takashi Amano. This shrimp is a very effective Thread/Hair algae eater. Besides algae it will also help to recycle dead plant matter and fish waste, breaking it down to smaller organic particles which bacteria can consume.
This shrimp also feeds on bacteria and micro-organisms preventing them from over populating the system.

Malaysian Trumpet Snail is very effective in aerating the substrate’s top layer keeping the Oxidizing Microzone aerated. It spends most of it’s time digging through the substrate in search for bacteria, micro-organisms and dead organic matter.

Otocinclus catfish which grows to just about 5 cm is a very useful addition in planted aquariums. This tiny fish will clean plant leaves from Diatoms and bacteria film.

Siamese Algae Eater (Crossocheilus siamensis) is the most effective fish in eradicating the Black Beard Algae (BBA). It grows to approx 14 cm and for that reason is not suitable for smaller tanks (fish requirements)

Neritina sp. Zebra is another snail worth keeping. It is particularly effective at eating the Green Beard algae and Green Spot algae which tend to grow on rocks and wood. Remember not to stock too many because they will start laying white eggs all over the aquarium which can look unsightly to some people. These eggs can’t hatch in fresh water.

CONCLUSION;
It is not that hard to achieve a balanced planted Ecosystem once you put certain things into perspective.
First of all find the right planted tank method, one which will suit your goals and your life style.
Cycle the soils by using the “Dry Start” method.
Plant heavily and stick to the dosing routine (right balance between the lights, CO2 and nutrients).
Prune the plants regularly and keep good hygiene (clean filters, light vacuuming and regular water change).
Rather under stock with fish (this will keep the organics low).
Stock the tank with fish and shrimps which will help removing organics and minor algae.

I compare the Aquatic Ecosystem with us humans. We need balanced diet, good hygiene and good environment to keep us healthy. The same can be applied to plants, fish and crustaceans.

Article  and photos by Dusko Bojic

This article originally appeared at

http://lowlightlowtechplanted.blogspot.com/

DIY Clay Fertilizer Balls

  By robert | August 27, 2011 - 11:22 pm | Aquarium Plants, The Low Tech Plant Tank
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Clay Fertilizer Balls
by Steve Pushak

Ingredients:

You have to obtain some clay that is about the consistency of plasticine. Pottery clay is available from pottery supply outlets for about $20 for 20 Kg. You could also use powdered clay & mix it with water or get clay from a ditch or cut bank. You need some fertilizer; I like to use slow release coated Osmocote ™ which contains ammonium nitrate. Many kinds of fertilizers have been used; there’s no rule which says you can’t use a different kind of fertilizer. I can’t really tell you what is the best to use; I don’t think it makes a big difference but I would recommend staying with ammonium nitrate or perhaps another nitrate fertilizer. I know people who use chelated trace nutrients & other fertilizers of all kinds. I’ve even put F-T-E, Fritted Trace Elements, into clay balls. I couldn’t observe any improvement beyond the use of basic nitrogen fertilizers but I can say that there weren’t any overt undesirable side-effects. I couldn’t tell you if my plants were grateful or not, for the most part, they seemed to feign indifference to these minor improvements.

Construction:

You take a glob of clay & flatten it out. Press about 10-15 granules of fertilizer into the clay ball & form it around the fertilizer to enclose it completely. Roll it between the palms until its the shape of a marble. There’s no rule about how many granules you have to use; I just flatten my clay glob out & glom it onto a small cluster of fertilizer that I spread on the work surface. If any bits of fertilizer are exposed, you can cover them with another little blob of clay. Repeat this operation a dozen or a hundred times until you have enough clay balls to satisfy your needs or exhaust your dedication to the task. Let them dry hard. Drying can be speeded up by placing the damp clay balls onto newspaper, improving air circulation, heat or by other tricks which you can dream up. Or you can just ignore them for a few days as I do. When the balls are dry, they are ready to use. They are probably ok to use even when not dry; as I say, there are no rules. Remember that they get water logged a few hours after they are submerged. Perhaps they are easier to poke in when they are hard and you don’t have to worry about squashing them open as might happen when soft. I prefer to think that the drying process helps to chemically bind nutrients to the crystalline edges & corners of the clay micro-particles and that these weak bonds help to occlude the nutrients later when they are submerged. I wear rubber gloves when I’m working with clay since it rapidly draws the oils from your skin & can cause skin problems. Powdered clay contains silicates so you should take care not to inhale clay dust; its not good for your lungs a-tall.

Packaging:

I put my balls into plastic snack bags, ten to a bag. You could go 12 to a bag to make an even dozen or 4, 8, 7 or 13 for any numerological or superstitious reasons of your own. I use ten because its the number of my fingers. I deny any metaphysical motivations for my choice, however the reader is free to draw his own conclusions. I package them only for convenience of storage, handling & sales; an alternative is to place them in decorative bowls conveniently strewn about your recreation room. Be sure your guests don’t mistake them for chocolates, unless of course your guests are of the undesirable sort.

Application in existing aquariums:

Poke several dried balls down into the substrate about an inch from the main stem of the plant all around it. I push them down to a depth about to my second knuckle. The more I install, the deeper I install them. You want the balls to be quite close to the roots for reasons that will be explained below. I only use the balls on Crypts, Sword plants and Aponogetons. There’s no rule that prevents you from fertilizing stem plants however I find that most stem plants grow too rapidly in my tanks for my preferences and require very little encouragement.

Application in new aquariums:

I usually install a layer of soil-mud mixed with a little peat & micronized iron into my empty sterilized tank. If I know the placement of my key feature plants such as a centre piece Sword then I will put the clay balls directly into the mud while its still plastic. I let the mud dry until its quite hard. If I’m in a rush, I will put several layers of newspaper onto the mud to absorb moisture. I remove the newspapers the next day & hopefully there is no surface moisture visible. If there is, the aquarium can be cloudy later when it is filled. Once the mud is dry, I can situate my plants according to the planting scheme, starting from one end & working to toward the opposite end. Planting is always much easier when there is no water in the aquarium for at least three reasons: a) you can see what you are doing b) plants don’t get disturbed & float to the surface c) my armpits & sleeves stay dry. I add a small pile of gravel into the corner to a depth of about 1″, lay the plant specimen with its leaves lying across the gravel surface & the roots nicely spread out onto the mud layer. At this time, clay balls can be placed between the roots, near to the plant stem. Another scoop of gravel is placed onto the roots & I gently position the plant stem the way I want it. It doesn’t have to be perfectly vertical since the plant may not be rigid enough & I don’t want to cover the leaves with gravel as I work across the tank. Once all the roots are covered with a nice layer of gravel, I can fuss with the plants a little bit, add some water & fuss a bit more. I find that I disturb the gravel the least if I place an empty tin can sideways onto the substrate & position the fill tube of the Python inside the can so that it is also lying lengthwise on the tank bottom. The tin can prevents the water current from disturbing the plants before they have anchored themselves & prevents digging channels into the gravel or creating a mud cloud.

Application in pots:

When I first install a plant into a soil pot, I fill the pot with a mixture of mud, peat & micronized iron and anything else that strikes my fancy. I’ve been known to put a 1/4 teaspoon of bone meal and/or a 1/4 teaspoon of hydrated lime mixed into soil however that is a digression. This is a good time to install 3 or 4 clay fertilizer balls intertwined with the roots of the potted subject. Then I cover the roots & clay balls with aquarium gravel, position the subject upright and plunk the whole caboodle into the tank. I often dry the soil mud in my pots weeks or months in advance. Its easy to prepare a half dozen pots in this way, than to try to make one in a hurry the day after I’ve acquired a fantastic new specimen that simply must be planted immediately. I take comfort that the drying process prevents any stray puffs of muddy water form occurring upon submergence and helps to chemically bond ions into the crystal structures of the soil particles. The clay ball needs to be placed right next to the roots so that the root hairs can grow into the ball for sustenance. This is critical for success.

How it works:

Clay is, by definition, comprised of extremely fine particles less than 0.002mm in diameter typically an amorphous mixture of alumina-silicates. The purpose is to form a dense barrier to slow down the diffusion of nutrient ions into the aquarium water. Clay is the least permeable natural material available aside from solid igneous rock. I will defer to Roger Miller on the subject of rocks or clay since this is just one of his domains of expertise. The diffusion of nutrients through clay is very slow, much slower than it would be through agar for example. The more you want to reduce the rate of diffusion, the larger the layer of clay surrounding the nutrients in the core should be. Be aware that if your clay balls are soft when installed its easy to damage them if you use the finger push method. If they have flaws or cracks, these will permit water to circulate directly to the fertilizer prills resulting in a higher rate of diffusion into the aquarium water. Generally you want the plant to extract the nutrients by its roots, not by diffusion or leakage into the aquarium water.

The roots of aquatic plants will grow toward a nutrient source by a process termed chemotropism. See Some nutrients passively diffuse toward the roots or into the water. Nutrient uptake is accelerated when the root hairs come into very close proximity of nutrients. Root cells do this by pumping hydrogen ions (protons) into the rhizosphere, “the soil zone immediately surrounding plant roots, which is modified by the increased number of micro organisms (e.g. Rhizobia) that live there, in association with plant roots”. See . This causes a negative charge on the root membranes and positive ions, cations, are electrically drawn into the root hairs. The rhizosphere is a zone of higher oxygen content which helps to protect the aquatic plant roots from damage by corrosive chemicals such as ammonia which naturally occur from decomposition in the absence of oxygen. A short distance away from a root fibre, there will be a low oxygen zone where anaerobic bacteria are using nitrates and sulphates as electron donors to fuel biochemical activities. These reducing zones are where iron & phosphates become reduced and soluble. Microscopic root hairs grow out from the root fibres and extend right into the reduced zones in order to access iron & other nutrients. These root hairs can absorb ammonia, nitrites & nitrates. Within the roots, toxic ammonia is converted to amides or ureides prior to entering the vascular system of the plant where it is moved up into the shoots where it is again converted to amino acids or to ammonia, enzymes to drive cellular processes which create simple sugars and complex proteins. Nitrates & nitrites can be circulated directly within the vascular system however they must be reduced back to ammonia via nitrogen reductase & nitrite reductase enzymes before they can be metabolized. According to my references (albeit relating to terrestrial growth), its best to maintain a balance of nitrates and ammonia. Too much ammonia results in acidification of the rhizosphere. This is why I recommend ammonium nitrate based fertilizer. See

I recently conducted a trial using clay balls with urea as the fertilizer. Urea readily breaks down to form ammonia; both are quite corrosive so take care in handling. I wanted to see if ammonia leached into the aquarium and if the roots of the subject plants were damaged in any way by these small, localized pockets of ammonia/urea. Since I used quite a lot of urea, I did end up with measurable ammonia in the water, enough to create a minor problem with green water but not enough to bother the fish. The plants have been growing quite well, especially the primary subject, a small ruffled sword, which has become quite robust now. It had been languishing previously. No damage to the roots is evident at this time; at least none this is discernable from external observation of the robust growth of the subject.

It has been pointed out that aquatic plants can easily satisfy their nitrogen requirements entirely from the water. This is quite correct. The strategy with clay fertilizer balls is to provide a more continuous supply of nitrogen and to target specific plants. I suspect that you could also provide nitrogen almost entirely from the clay balls. General growth in the aquarium will not be as lush as with regular hydroponic additions of nitrate but lush growth has its draw-backs too. I would hesitate to rely solely upon geoponic nitrogen for Lace plants; to ensure vigorous growth & the long term viability of the rhizome, one should still add hydroponic nitrogen.

I’ve estimated that clay balls continue to provide nutrients for 6 months or more however I have no concrete evidence to support this aside from subjective observations of my own & others. Of course it depends upon how big the clay balls are, how much nutrients are placed within them & serendipity according to how well the plant roots get into the supply. You may only need a single application to grow a large vigorous sword plant, a couple feet in diameter. Plants such as Swords or Lace plants can grow very vigorously and large. A lace plant can throw off new leaves every few days; the growth rate is simply prodigious! I suspect that you would not overfeed these plants by adding more clay balls in six months or so. I have had my best results with augmenting potassium nitrate to the aquarium water regularly; sufficient nitrogen is a key factor to success with the Lace plant. It is my opinion that many so-called dormant lace plants were simply the result of insufficient nutrients, especially nitrogen, when the stored reserves in the rhizome are exhausted.

Paul Krombholz has observed that Lace plants do not seem to do as well in strong reducing substrates while others have had tremendous success growing them even in composted manure substrates. Its important to realize that manure would provide an abundant supply of nitrogen for several months. Lately we have been getting Lace plant specimens that grow extremely well in aquariums. Is this simply because we understand & provide the nutrients required for this plant or do we have a mutated specimen? Perhaps both. Rapid growth mutations occur commonly in the artificial environment of the aquarium but which might not be competitive in a natural environment.

Sources:

I will sell ready made mail order clay balls in any amount. In large amounts they wholesale for $0.25 each and sell retail in stores at $5 for a bag of 10. At club auctions, they have sold for $20-25 for a bag of a hundred. Clubs are welcome to place a bulk order; I can supply retailers or distributors if anyone business minded is interested.

You can contact me by email at teban@powersonic.bc.ca, by phone at 604-591-5512 or by post:

Steve Pushak
11451-80A Ave
Delta, BC
V4C 1Y8
CANADA

A 50 Gallon natural plant tank by Diana Walstad

  By robert | May 14, 2011 - 3:24 am | The Low Tech Plant Tank
1 Comment

Diana Walstad

by Diana Walstad

 

I reset up this 50 gal tank in May 1993. I layered the tank bottom (1.5 ft X 3 ft) with 3 gal of topsoil mixed with 3 tablespoons of powered dolomite lime (to bring soil pH up). Soil was top layer from a nearby pasture and is a typical Southeastern red clay soil, nothing special. I covered soil with about 1.5 inches of gravel.

Lighting is from a window (Western exposure) and two strip lights containing a miscellaneous assortment of three 30 watt fluorescent bulbs (Phillips Home Light, Sylvania DayLight, and a Penn-Plax “aquari-lux”).

I use well water, which is quite hard (GH = 17). I filtered the tank for many years with an Eheim canister filter, but about 3 years ago I substituted it with a $15 internal pump (Aquarium Systems “Mini-Jet 606″). I made my own “hose return” by attaching and stoppering plastic tubing (with drilled holes) to the pump’s outlet.

The hose return provides a moderately strong current across the tank. Amazon swordplants have always dominated this tank making it difficult to keep anything else in the tank except Anubias, Java fern and Cryptocoryne wendtii.

About a year ago I took a razor blade to the most dominating Amazon swordplant and sliced off the entire top part, in essence, killing it. I left the root system intact, because I didn’t want to create a mammoth mess in the tank (I don’t mind uprooting smaller plants). Not unexpectedly, there were consequences. Within a few months there was significant algal growth in the tank and an opaque film on tank’s surface.

I’m sure that the dying root matter released plenty of organic matter and chelated iron. I added an apple snail, floating water lettuce, potted plants, and just waited. Tank is recovering nicely (as expected). Fish were fine throughout.

Now I keep the 3 remaining Amazon swordplants either in pots or severely pruned. Cryptocoryne usteriana, which has beautiful leaves of 2-3 ft length, has reproduced.

Recently, I added a small clay pot containing a couple stems of Rotala macrandra. The plants, which have done poorly in the past when simply stuck into the substrate, have surprised me with their good growth in the pot (see photo).

The Rotala are potted in a small clay pot containing a brand of potting soil that seems to work very well for plants, at least in pots (I haven’t tried it as a tank substrate yet). The potting soil I used is: “Miracle Grow” Potting Mix listed as containing 50-60% Sphagnum moss, composted bark fines, perlite, wetting agent, and inorganic fertilizers; N:P:K =0.18%:0.06%:0.12%. Although it contains fertilizers, I detected (after 3 days submergence) no significant ammonia or nitrite release in a “bottle test”.

For potting plants, I generally, cover the bottom hole of a clay pot with a stone or a big gravel piece (from the driveway), then about a ½” layer of aquarium gravel, about 1-2 inchs of potting soil, and then a top ½” layer of gravel.

Unlike my 45 gal, mulm collects in this tank. So I gravel vacuum about every month or two resulting in a 10% water change. The Rainbowfish have thrived in this tank for many years and haven’t “missed a beat” since I replaced the canister filter with the Mini-jet pump.

 

Setting up a Walstad Natural Planted Tank.

  By robert | February 15, 2011 - 6:00 pm | The Low Tech Plant Tank
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Written by Betty, DataGuru   
     
In her book, Ecology of the Planted Aquarium: A Practical Manual and Scientific Treatise for the Home Aquarist, Diana Walstad says the goal is to set up an ecosystem where “plants and fish balance each other’s needs”. In this type of tank, the plants are the water purifiers rather than the usual filters. Rather than converting ammonia to nitrAte, plants convert ammonia to plant mass, so there’s no buildup of nitrate and pH doesn’t drop over time. Plants also remove heavy metals from the water. Fish food, mulm and micronutrients from the soil feed the plants. Fish and bacteria produce carbon dioxide for the plants and the plants help produce oxygen for the fish. Only moderate lighting combined with sunlight is needed. A Walstad-type natural planted tank is low maintenance requiring only pruning of plants and infrequent partial water changes.My 29 gallon bowfront pictured above, was set up as a natural planted tank in January, 2005, this is what it looked like eight months later. The substrate is an inch of topsoil amended with crushed oyster shell, covered by an inch of small gravel. Plants include pygmy chain swords, sagittaria subulata, an amazon sword, and hygrophilia difformis (wysteria). Inhabitants include swordtails, Endler’s Livebearers, a clown pleco, ramshorn and pond snails. Lighting is sunlight from a south window and 40 watts of 6500K compact fluorescent light.

How to set up a Walstad-

 

type natural planted tank:

 

Substrate:

One to 1.5 inches of unsterilized garden soil, potting soil or topsoil with 1 to 1.5 inches of 2-4mm gravel on top. Don’t use subsoils or clay soils from areas near brackish water. If the soil is acidic, you can use powdered dolomite lime mixed in. If you have soft water add pelleted dolomite lime, or crushed shells to gradually increase the level of hard water nutrients over time. She recommends not adding peat or fertilizers (including manure). Adding a small amount of well-decayed organic matter/compost is fine. You may want to set up a bottle test to see how much the soil yellows the water. Add a layer of soil and cover it with a layer of gravel and then add water being careful not to disturb the soil. Then let it sit for several weeks. Some soils leach more than others. When using bagged soil, it would be a good idea to spread it in a thin layer and let it air out over night to gas out ammonia.

Plants:

Use lots of different plants, some of which will eventually grow emergent. Use floating plants too. Generally cheaper plants are easier to grow.

Fish:

Diana says you can immediately moderately stock the tank. (Keep an eye on ammonia, because I’ve had soil that immediately cycled a tank and other soil that took a month to be habitable.) Avoid plant eaters or fish that dig in the substrate.

Lighting:

Diana prefers a mix of sunlight and fluorescent lighting–one to two watts per gallon if the tank does not receive sunlight, less if the tank receives sunlight. She likes to use a combination of cool white and plant grow light fluorescent bulbs. Avoid tanks taller than 18 inches unless the tank will receive sunlight. She recommends a timer set to 10-14 hours of light per day.

Filtration:

Her book says that all you need is water movement, though these days, Diana recommends using mechanical filtration as well. A power head with a pre-filter works fine.

Fertilization:

Feed the fish liberally.

Water changes:

50% every 6 months, or if fish or plants look unhappy. Mulm feeds the plants.

Aeration:

only if the fish are piping/gasping in the early morning hours.

Misc:

snails are good for cleaning plant leaves and speeding up the decomposition process (that provides nutrients and CO2 for plants). She recommends water hardness of > 7dh.

Putting it together:

Add one inch of topsoil and amend with crushed shells, mix well and smooth. Add just enough water to wet the soil. Then add a layer of gravel around the edges of the tank. Set each plant and add gravel around it. After you have all the plants in, fill in with gravel until you have an one to 1.5 inches of gravel. Place a plate or shallow dish on the bottom of the aquarium and carefully add water. If the water is cloudy after you have three or four inches of water in the tank, syphon it out and refill. Diana usually adds fish immediately, but I like to wait and check the water parameters the next day to make sure the soil isn’t releasing ammonia. Here is a step by step pictoral guide to setting up a Walstad-type natural planted tank.

This article also appears on the GAB web site

Low tech planted tank the Walstad way

  By robert | January 3, 2011 - 11:22 pm | The Low Tech Plant Tank
1 Comment

By Robert Paul Hudson

While much attention is brought to methods in aquatic gardening that involve high tech devices such as C02 systems and intensive lighting because ethey produce rapid growth in plants, there is another methodology often referred to as “low tech”. This approach to planted aquariums has often focused around the book Ecology of the Planted Aquarium by Diana Walstad. I had an opportunity to speak to Ms. Walstad.

Ms. Walstad received a B.S. in Microbiology from the University of Kentucky (Lexington) in 1968, and says she was born into a family that always had aquariums and ponds. Other than a brief stint in the Peace Corps, she has worked as a research technician all her life. “I worked in several medically related fields for the University of North Carolina (Chapel Hill) until 2001. Currently, I am working for the federal government as a cell biologist in a much more esoteric field- intracellular signaling.”

For someone who has not read your book, please briefly describe what the main points and objectives are.

The overall goal of this book is to get aquarium hobbyists to better appreciate plants. Plants aren’t vital for fish survival, but they can still play an important role in the aquarium. For example, plants keep algae in check, take up toxic ammonia, recycle fish food wastes, and oxygenate the substrate. Plants reduce the need for frequent water changes and gravel cleaning while still keeping the fish healthy.

The book also explains how plants affect the aquarium ecosystem and what factors affect the plants. For this I use scientific information that few hobbyists have ever seen. Then I describe my own aquariums and “my method”. However, I’m much more interested in providing information that hobbyists can use to set up their tanks the way they want. To this end, many hobbyists use the book’s information to better maintain their High Tech planted tanks.

I understand Ecology of the Planted Aquarium was the culmination of many years of work. Could you describe the process, what first inspired you and what your original goal was for the project?

Believe me, there was no planned project to write a book. The process really started in 1988 when I decided, after a long dry spell without tanks, to once again set up an aquarium. This time I was determined to have a planted tank. All past attempts had failed, so this time I decided to try something different- use soil in the tank. Ironically, I was inspired by a 1988 FAMA article (“Magic Touch or Common Sense?”), which was an interview with the plant enthusiast Dorothy Reimer. She described using potting soil to get spectacular plant growth. When I too used potting soil and got spectacular plant growth, I was converted. I also noticed that my fish were doing very well in these tanks with minimal tank maintenance. I decided to try writing narrowly focused articles based on scientific information. Thus, I wrote many articles for FAMA and TAG (The Aquatic Gardeners Association) on the preference of aquatic plants for ammonia (not nitrates), allelopathy, submerged soil chemistry, fish food as a source of plant nutrients, etc. The positive response from readers kept me going. Eventually, these articles would become chapters (or sub-chapters) of the book. At some point, I wondered if I could mesh all the magazine articles I’d written on so many seemingly unrelated topics (allelopathy, ammonia preference by plants, metal toxicity, etc) into a book. I decided that it could be done, and more importantly, that it was worth doing.

Did it evolve as you envisioned or were there any surprises?
There were many surprises. Every scientific paper might have a new surprise. It was exhilarating. There were days when I couldn’t wait to get to the libraries. The little experiments I did also provided some surprises, like finding less plant growth in potting soil with added fertilizers than without added fertilizers. It’s empowering to do experiments to test out a theory. When I plan an experiment, I am often spurred on by the realization that I might discover something that no one else in the entire world knows.

The big surprise, not as much fun, was my experience with book publishers. It seems my book wasn’t academic enough for university libraries but it was “too scientific” for hobbyists. I spent a couple of frustrating years trying to find a publisher. If I had finally contracted with the university publisher that was interested, the book would have been severely condensed, cost $70, and would be purchased by only a few academic libraries. Certainly, no interviews for FAMA! I ended up publishing it myself, so that it came out exactly the way I wanted it.

The hobby has changed in many ways since you first began your research. Do you think the hobbyist today is attracted to the principles of your book for the same reason you originally intended?

Yes. I think hobbyists are attracted to the concepts in the book for the same reason that I was. These concepts also have real world applications. For example, we’ve all read about environmental efforts to use wetlands to clean up waterways. In my book, I advocate using floating/emergent plants in aquariums to control algae. Both things are based on the “aerial advantage”- that all floating/emergent plants (i.e., wetland plants) can use air CO2 that algae doesn’t have access to, are prodigiously fast-growers, and can quickly drain nutrients from the water.

Your methodology is often described as a low-tech approach. I do not see it in that simple of terms. I see it as attractive for the challenge of applying the scientific principles and seeing the effort come to fruition, rather than simply an approach to avoid the cost of high tech equipment. Your most avid followers seem to have a passion that goes far beyond just saving pennies. Is that an accurate observation that you feel compliments the intent of your work?

Yes. I think you’re right. I’m delighted that people see my book as more than just saving pennies. Aquariums are truly fascinating. They have so much to teach us.
Diana feels her work on the subject is complete other than small future updates to the book. Betty Harris of Norman, Oklahoma found the book two years ago and says “It is chock full of scientific information on the ecology of planted tanks.” She feels the book has made a tremendous difference. “ It’s made keeping plants happy easy! You don’t have to tinker with water fertilizers or add CO2. Just add soil, plants, supply a decent amount of light and you’re set,” she exclaims. Betty has even set up information on a WEB page that provides a summary of the book’s methods as well as a step- by step demo of a tank set up. http://thegab.org/Articles/WalstadTank.html

While some Walstad followers contend any aquarium plant may grow well with this methodology, there is an assumption that slow growing rooted plants will thrive more than very delicate and more finicky stem plants. I will focus on two such plants that deserve to be in the spotlight.

Nuphar japonica
From lakes and rivers in Japan, the light green almost translucent leaves make this water lily an especially decorative plant in the aquarium. It grows from a thick creeping rhizome that looks like a chunk of raw pineapple. The growth is slow so that it is easily managed and rarely do the leaves reach the water surface when lighting is more subdued.

Sagittaria subulata
Called “dwarf sag” this grass like plant grows easily in the aquarium with little effort. Above the water the leaves take on a spoon like shape. Underwater the plant reaches a maximum height of about six inches and may be trimmed to maintain a shorter height.
Both of these plants are a worthy addition to any freshwater aquarium and thrive with little special attention