Aqua Soil

Rodgie_III

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Nov 17, 2017
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Greetings everyone,

I’m close in setting up a low tech tank (D. Walstad) method. But I’m leaning towards using AS. But, my biggest concern, does it also release Carbon for plants to use like regular potting soil does? I know that Co2 is given by bacteria when they eat. But thinking about the very beginning (1-7 days) of set up. If AS doesn’t have those bacteria’s yet, will it be successful?

Cheers,
 

Allwissend

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short answer no, what is AS will not provide bacteria with enough organic matter to supply the same levels of CO2 as potting soil.

As I understood the method described in Walstad's book, the organic material that is present in the soil will decompose over (long) time to provide some low amount of CO2. More CO2 will be added by fish respiration, decomposing food, fish waste and DOC. This attempts to target the main CO2 reservoirs present in nature. However keep in mind in nature you often have 1m+ deep rich organic detritus bed and most plants just want to reach the atmosphere where CO2 is abundant. So yeah... not like nature at all.

Regarding the presence of bacteria in potting soil vs AS:
Bacteria in potting soil will mostly not be the right kind that exists underwater and in anaerobic conditions. So you pretty much have to start at square 1 as well. Even more some unknown amount of NH3 will be readily made soluble.
AS also should not have significant bacteria and will leak less NH3 in the water. It is the NH3 that will start the nitrification cycle.

With both water changes in the first weeks should be frequent. When I did topsoil aquariums, I found they were most easy to work with after 6 months. Before that it was hit or miss...
 

Tim Harrison

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It's the decomposition of organic matter in potting compost that results in CO2 evolution. You are likely to get very little by comparison from AS.
I find that if I plant heavily from the get go my tanks usually cycle within a week, that is using potting compost or AS.
There will be enough bacteria on the roots of the plants to inoculate the substate. The initial ammonia spike will be enough to cycle a tank.
The signature link below may help.
 

Rodgie_III

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Nov 17, 2017
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Thank you both for the response. Will a combination of AS and regular miracle gro soil work?
 

Tim Harrison

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You don't really need to use both. If it's the release of CO2 you're after just use a potting soil with a high organic matter content like peat moss. I use a mix of 1:1 peat moss and potting compost, capped with sand or gravel and that usually works well.
If you don't want to be bothered with layering substrate just use AS.
Either way if you want additional carbon but don't want to inject CO2 you have the option of LC like Seachem Flourish Excel.
 
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Rodgie_III

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Nov 17, 2017
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Hi guys,

Right now my AS order can’t be cancelled anymore. That’s why I’m thinking of at least using some of it as a cap on top of a potting soil. When we say overkill, is it a disadvantage?

I’m not going to the excel path, I’ll try to make this work. But, first I wanna know if you guys think that the size, weight, and texture of AS is ideal as a cap. And, is there any disadvantage in the future because they both will release some ammonia.

Plus I’ll have to spend close to 20 bucks again to buy both gravel and miracle gro through Amazon. I wish I followed my guts in the beginning.

Anyways let me know guys.

Thank you
 

Tim Harrison

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I wouldn't use AS as a cap it's a bit lightweight and it'll be easy to disturb the soil below.
If you are determined to use it perhaps give some thought to using a gravel tidy in between to keep the soil contained. I sometimes use this material https://www.amazon.co.uk/Gardman-Gr...93&sr=8-1&keywords=gardman+greenhouse+shading

upload_2017-12-29_18-35-9.png
 
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Rodgie_III

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Nov 17, 2017
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I see, that’s one of the worries I have in mind. I guess I’ll just try to return the AS and buy a gravel and potting soil.

That mesh you shared isn’t available here in US. Thanks Tim
 

Allwissend

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Yes AS is far from ideal in that it is not heavy enough to keep the fine soil particles down and it is not dense enough to form a nice barrier which reduces somewhat the transfer between soil and water column. It is so light that I was on the verge of throwing my pair of pincers in frustration earlier today after trying the 5th time to put in a stem... feeling like a newb all over again.

If it were my aquarium at this moment I would just go with pure AS. It has some nutrients for the roots and you will have a lot less problems to deal with and "what if" questions that come with topsoil. You can have a low tech tank with water column fertilization... there is an article about EI for low tech aquariums
 

Rodgie_III

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Nov 17, 2017
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I can dose water column with dry ferts, I have that. What I don’t have and don’t wanna do is dose Co2 everyday. That’s why I’m making sure if AS can do the same with potting soil. But upon research it looks like it’s not gonna happen. I’ll just end up returning it and buy what I really need. Thanks for the inputs guys though.