# How to tell if your substrate is going anerobic?



## joemomma (Apr 7, 2006)

How can you tell if your substrate is going anerobic (the condition which we don't want I think)? Is there an easy way to tell? Where are likely trouble spots - under driftwood, corners, etc? How do you combat it in these trouble spots?


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## Glouglou (Feb 21, 2006)

*Aerobic and anaerobic*

I Joe, I'm relatively new to the El-Natural forum. If you look at the post I suggest in * About undergravel filter????* the discussion is all about aerobic and anaerobic.

What I learned about using soil in aquarium is to have an anaerobic bottom and aerobic top.

The anaerobic will keep Iron and other oxide in a available form and permit the formation of roots hair in plants. The aerobic soil habited by nitrifyng bacteria eliminate sulfide and other undesirable stuff coming from the anaerobic bottom layer and transform nitrite (coming from anaerobic) in nitrate.

Everything have to do with what type of material you use and to work in strata where you decide where is the anaerobic part and aerobic part.

The following link show you with some detail the chemistry beyond all that:

http://home.infinet.net/teban/substrat.htm#Submerged_Soil_Properties


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## dwalstad (Apr 14, 2006)

joemomma said:


> How can you tell if your substrate is going anerobic (the condition which we don't want I think)? Is there an easy way to tell? Where are likely trouble spots - under driftwood, corners, etc? How do you combat it in these trouble spots?


Major anaerobic problems are when plants with blackened roots dislodge and float to the top. Or when bottom-dwelling fish lose their appetite (H2S toxicity).

You have correctly identified potential trouble spots, especially fresh potting soil sealed over by a big piece of driftwood. You can remedy the situation by poking sequestered area with a knife to introduce some oxygen-containing water.

I've never put driftwood into my tanks, and I just plant the entire bottom. So what you're describing is a new situation. However, you are ahead of the game by thinking ahead. If you use driftwood, which seals off the substrate from oxygen-containing water, you might have to do some extra work until the substrate safely "settles down".


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## joemomma (Apr 7, 2006)

Thanks for the input! As for how long it will take for the soil to settle, I'm not sure, I imagine it varies tremendously based on the soils used. The tank had been setup for about three weeks before I added the driftwood, so I may be OK. If nothing else, I'll poke around a bit with something under the driftwood next time I do a water change. (I'm only changing water because of tannins from the driftwood leaching into the water - I was not dilligent in my soaking of the wood)...


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## dwalstad (Apr 14, 2006)

I recommend vigilance!


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## Crispdx (May 17, 2006)

Are bubbles from the substrate always a bad sign, or are there benign explanations?


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## sb483 (May 29, 2006)

Crispdx said:


> Are bubbles from the substrate always a bad sign, or are there benign explanations?


From Ecology of the Planted Aquarium, Chapter on Bacteria:
If there are growing, healthy rooted plants in the aquarium, bubbles from the substrate are a good thing - oxygenated water is rushing in to fill up the space left as the bubbles float up.

If none of the rooted plants are doing well, then bubbling from the substrate is a reason to worry (fish probably won't be doing well either).


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## sb483 (May 29, 2006)

(sorry, double post)


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## Crispdx (May 17, 2006)

_From Ecology of the Planted Aquarium, Chapter on Bacteria:_

Thanks. I guess I'll have to get a second copy to keep at work for when questions like that pop into my head!


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