# Corydoras/ Anaerobic Substrate



## Haseq (Jun 26, 2010)

Hello,
I am interested in creating a soil substrate aquarium with plants as filtration. I want to keep a Corydoras species in the tank and provide the Cory's with ample surface on the bottom since they live there. My question is: If I were to have half (50%) of my bottom surface without plants, will that part of the substrate suffer from the lack of oxygen that plant roots can provide. Will the substrate become toxic to the fish?

I thank you for any help! It is much appreciated.

Hans


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## davemonkey (Mar 29, 2008)

I don't think you'll have a toxic substrate with part of it unplanted. However, I think cory cats can be happy in a heavily planted tank. I know a guy who has an extremely heavily planted tank (foreground is mostly _Marselia sp_. ) and his cory cats seem to enjoy the thick cover of plants to play/hide in.


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## mhamm3650 (Feb 23, 2010)

I set up my 10 gallon tank with a soil substrate and left a corner (About 1/4 of the tank) unplanted so my pair of German Blue Rams would have some free swimming space. I did not add any soil under the gravel of the free corner and, like you was concerned that this corner would turn toxic. 

German Blue Rams can be sensitive. To be on the safe side I vacuum the gravel of the free corner to get rid of excess waste and algae once every 2-3 weeks. 

This is the first time I have set up a NPT and the first time I have kept Rams. I'm pleased to say that both are doing well. 

I think it would be safe to say that your corys will do fine if you leave part of the tank unplanted. If you put soil under the no plant end of the tank roots will eventually find their way there. I don't think you will have anything to worry about.


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## mudboots (Jun 24, 2009)

I tried a tank with lots of open areas for my 13 cories and noticed they always stayed where the foreground plants were growing. Now that I've let the foreground fill in they really love to get in and out of the jungle, and seem to appreciate the densely planted foreground.


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