# El-natural aquarium without soil?



## rosse (Jan 29, 2007)

Hello,
At first I'd like to say I'm verry happy i found this forum with so much of useful information in it, and I'm sorry for my questions being so stupid . I'm very very new to aquariums and I don't want to make big mistakes in the future 

I have started my first aquarium a week ago, and its not really what it "should be", according to D.Walstad book and her method (Thank you very much for your book, Diana!). Here are some details on aquarium itself:

*Tank size:*

80x35x35cm, ~100 l (~28 g)
*Substrate:*

Thin layer of peat (about 1 cm thick) in the back of tank
5-8mm fraction gravel (about 3-6 cm thick)
*Lighting, filtration:*

Internal filter (~320 liters/hour) for moving water around and a bit for mechanical filtration
2x18w osram flora, 1x18w osram cool white lamps (~0.5 w/liter)
*Fishes*

10 x Albino zebra danios (Danio Rerio)
*Plants*

Vallisneria Spiralis
Cryptocorine wendtii
Echinodorus mercedes
Ceratophyllum Demersum
Rotala Rotundifolia
Hygrophila Polysperma 'rosanervig'
Heteranthera Zosterifolia
Hydrocotyle Leucocephala
Egeria Densa
Ludwigia repens
Microsorum pteropus
Vesicularia dubyana
Anubias barteri var. nana

Well as you can see, what i meant by saying that tank is not really "true" natural tank, was that there is no soil under gravel, except some peat. Should I be worried about that? I want to make as less intervention to aquarium life as possible (No fertilizers etc).

In Diana's book she says that "organic matter contains all the elements that plants require", so i thought that decomposition of organic matter in peat (it contains >90% organic) would be enough to feed rooted plants. But in the other thread she says that peat is not good choice for a substrate. Could someone clarify this?

I do not have lots of plants with "serious" roots. And (correct me if I'm wrong please) what soil substrate is about, is to provide some nutrients for plants which take them throught their roots and it does not have very significant meaning for floating or stem plants?

I see one possible problem with that - substrate becoming too anaerobic and releasing toxic chemicals to the water. Will those plants i have (vallisneria, two cryptocorines, echinodorus) be enough to keep gravel and peat oxidised? I also have snails (melanias (sorry if the name isnt right)) which are supposed to dig into gravel and oxygenate it.

What else am I missing? Is it possible to still have 'natural' tank without having soil as a substrate?

So far my tank has been running for a week and plants seem to be ok and growing (at least slowly). I have some algae issues too, but i guess (and hope) it's because of having not so many plants in the start and it will get better after plants grow a little. Should I expect something bad happening? Do I need to pay extra attention to something?

Thank you for your critics, opinions, ideas, suggestions, and sorry once again for starting 'not-so-smart' thread. And sorry for my english 

For the end, here's the photo of my tank after a week:








In case it doesn't work, here's the link


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## Peter66 (Aug 18, 2006)

Since planting soil consists mainly of peat (at least in sweden) you should not be in too much trouble. I've read of plenty of people who had great success using only peat under gravel.


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## dwalstad (Apr 14, 2006)

rosse said:


> Hello,
> 
> In Diana's book she says that "organic matter contains all the elements that plants require", so i thought that decomposition of organic matter in peat (it contains >90% organic) would be enough to feed rooted plants. But in the other thread she says that peat is not good choice for a substrate. Could someone clarify this?


I took a look at the photos. Thanks for posting them.

Not all organic matter is alike. When I talked about organic matter containing all nutrients plants require, I was mainly referring to fishfood (p. 80). Fishfood is a particularly rich source of all plant nutrients. Next would be compost, then the organic matter in natural soils.

Peat has almost no nutrients (except carbon) and is extremely acidic. It has very little iron, so you don't get the soil advantage where the plants can get their iron from the substrate instead of the water. Also, plant roots are very much stimulated by soil phosphorus, and peat has almost no phosphorus.

I don't think you'll have to worry about it going anaerobic (bacteria that consume oxygen can't grow well in a peat soil). I'd worry more about poor and very slow plant growth.

The only good thing going for peat (as opposed to pure gravel) is that it will probably generate carbon dioxide for plants.

I'd make sure you have enough water hardness (GH of 4 or higher), so that your plants get enough calcium, magnesium and potassium.

You may get by with slow plant growth using your peat substrate and feeding the fish well. But I do not recommend a pure peat substrate.


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## rosse (Jan 29, 2007)

Thank you for your reply. My GH is 10, and this peat has ph of 5.5-6.5, at least thats what it says on pack of it. I will feed my fish well and hope that this will help my plants. 

Also, if i had soil substrate, would nutrients in it be available only for rooted plants, or does it give them away to water column, too? 

Thanks again rayer:


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## essabee (Oct 11, 2006)

Not all peat are alike. If the ph is between 5.5 and 6.5 I think you might be all right, there has to be a lot of un-decomposed organic matter so all nutrients have not leached away. At that ph you will have aerobic bacteria growth too.

About nutrients movement from substrate to water column, the answer is yes; but the rate of movement depends upon many factors, and finally the movement only tends to homogenize so finally you will have equal proportions of nutrients in substrate and water.


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## dwalstad (Apr 14, 2006)

rosse said:


> Thank you for your reply. My GH is 10, and this peat has ph of 5.5-6.5, at least thats what it says on pack of it. I will feed my fish well and hope that this will help my plants.
> 
> Also, if i had soil substrate, would nutrients in it be available only for rooted plants, or does it give them away to water column, too?
> 
> Thanks again rayer:


I'm glad to hear you've got hardwater. That will help.

Water and soil are very different in terms of their ability to provide nutrients to submerged plants.

Nitrates is the one major nutrient that does not bind to soil particles, so it is released into the overlying water. You would eventually get the homogenization that Essabe mentioned.

However, almost all other nutrients bind tightly to soil particles. Explanation: soil particles are negatively charged, so they attract positively charged nutrients (ammonia, calcium, magnesium, potassium, etc). Even though phosphate is negatively charged, it binds tightly to the positive charges on soil particles. Also, soil particles, especially clay, is often made up of considerable iron. Water contains almost no iron.

I wrote all about this in my chapter on substrates. In essence, ordinary soil contains huge amounts of nutrients that do not ordinarily enter the overlying water.


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## essabee (Oct 11, 2006)

The effect of clay colloids binding powers in soil is well known. Under-decomposed organic matter contains mineral colloids and nutrients, at least enough for the aquarium plants, who get most its nutrients by foliar feeding anyhow. Hard water, fish mulm, will move down through the gravel, plant roots will pump O2 into the soil, good enough to give the substrate supporting strength for the plants. I am not advocating the idea it is an ideal situation but a reasonable one for the plant substrate. No disaster expected by the condition.


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