Do snails take the oxygen out or away from other fish in a aquarium?

Question

Do snails take the oxygen out or away from other fish in a aquarium?

Answer 1

Snails don't really affect the oxygen level much but if they are the same species I have (the little brownish ones) they will breed like crazy & try to take over your tank. Even with all the snails my one tank has it doesn't seem to affect the oxygen. Do you have a air stone or any live plants?

Answer 2

Snails use oxygen like all other animals, but there really shouldn't be any concern of them suffocating your other fish.  As long as your filter creates sufficient surface agitation, there will be plenty of dissolved oxygen.  Also, if there is an oxygen deficiency, the snails will suffer well before the fish, and you'll see them climbing towards the top of the tank.