type of foam used in aquariums?

i bet the stuff in couches would work if you can be sure its chemical free. or just get some polyester batting material.

no no no no no ..that stuffs treated and not only that..its closed cell foam and its treated for fire retardedness.

DITTO on finaddict's advice, foam rubber is terrible junk to use.

I found some material that I just started using I found at Home Depot for $7 for a 36"X18"X1" sheet. It's blue, and looks identicle to some of the larger pads I've seen used in pond filters. It isn't really a foam, and is used as a "cut to fit" air filter. It's made from a polyester-looking fiber, and is about the texture of a scotch-brite pad. I've used it for a week so far in a canister filter, no harmful effects. Easy to cut to shape of the canister filter and stack the pads up. Cheap as dirt and effective so far. I use polyester floss just after it since this stuff is not quite fine enough to use as a final media.

I'm curious, is the foam that you are referring to that's closed cell and fire-retardent or is it the urethane-ether foam?

-- Ryan Chapin

I imagine he's talking about the insulation batting. They're mostly fire resistant, and they need to be closed cell to work efficently.