Concrete Filter

[Edgar 6]

Is concrete a safe material for fish? I have something like this at home and I was thinking of making it into a filter. I'm just not sure how safe the concrete would be for the fish.

Edited August 2, 2011 by Espectroundead

[shakaho 6,312]

Concrete can raise pH. If weathered long enough, it becomes safe. People soak it in water, bathe it with acid, etc. to weather it.

What kind of filter could you make from that?

[cometgirl 1]

One thing to worry about with concrete is whether it will raise your pH. Newer concrete can leach chemicals that will do this. You could test it by putting water in it and testing the pH immediately, then test again after a day or so to see if the pH goes up.

[Edgar 6]

Concrete can raise pH. If weathered long enough, it becomes safe. People soak it in water, bathe it with acid, etc. to weather it.

What kind of filter could you make from that?

The thing is very very old and it was used to hold water so i'm thinking all the chemicals probaly leeched out already. I was thinking of making some sort of bogfilter. I wanted to put bog plants on the shallow side and filter media on the deep side.

One thing to worry about with concrete is whether it will raise your pH. Newer concrete can leach chemicals that will do this. You could test it by putting water in it and testing the pH immediately, then test again after a day or so to see if the pH goes up.

Cool thanks, I'll do that tomorrow. It is pretty old so maybe it is safe to use by now.