# SOFT clay first layer? Bentonite?



## Monster Fish (Mar 15, 2011)

Clay by itself will dissolve in water. You need to bind it with soil or peat then cap it to keep it from getting into your water column.

I wouldn't use any of those clays listed. Polymer based clays will not have any iron. You need to get all natural red clay. Try an arts supply store or pottery store.

If you need to use clay powder, use the red iron oxide clay powder.


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## lookimawave (Feb 23, 2012)

Thanks for the reply! What sort of clayeat ratio do you think would work? Do you think I could do clayeat:sand? Any soil brand recommendations? I would really like to avoid soil with organic matter.

Do you know if polymer clay is toxic to fish? I have some anchoring plants right now (but no fish yet).


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## Monster Fish (Mar 15, 2011)

Only use a small amount of clay. Around 5-10% of your total substrate should be clay. Why would you want to avoid soil with organic matter? Well a better question would be, which type of organic matter do you want to avoid? Almost all bagged soils will have organic matter in it. You will need to thoroughly sift it and mineralize it if you want to eliminate most of the organic content.

Not sure if their toxic to fish. I just skip using polymers since they don't contain iron oxide.


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