What is filter foam made out of?

[finnfinnfriend]

Is it some type of polymer? I mean, could I stock up on it and store it for years before actually using it? That is, if I stored it in fairly gentle conditions...

[efg321]

I guess but would be VERY careful depending on what use it was for. There must be some standards for aquarium stuff. made from, etc

[finnfinnfriend]

Originally Posted by efg321

I guess but would be VERY careful depending on what use it was for. There must be some standards for aquarium stuff. made from, etc

Oh yeah. I woundn't use any sponge for an aquarium that wasn't specifically made for an aquarium.

[Hallyx]

Filter foam is an expanded polymer, probably polyethylene, cheap and biologically neutral. Like most plastics it will last indefinitely if kept out of the sun (UV) and not exposed to chemicals or smog.