Shells

[brian_moons]

I have some old sea shells lying around, would it be alright if i put them in my aquarium? after i washed them and stuff?

[OrionGirl]

They will alter your water chemistry--increase KH/pH. Might be fine, depending on your stock, or might make for some unhappy fish.

[Oddball~]

Yes, some fish do not like shells for some reason... I would wash them in dechlorinated water to be safe. I'm just really paranoid since I wouldn't want my $25 puffers each to die a death for an easily prevented reason.