DreamsInaBox
Member
I wasn't talking about O2 depletion though, I was just talking about CO2 poisoning. It's definitely possible to have too little O2 in your tank and suffocate your fish, but getting too much CO2 in the water is quite hard. And while a betta won't die from O2 depletion because they can breathe from the air, they can be poisoned with too much CO2.I killed off most of a tank by suffocation, it's not impossible. (Tank was neglected and evaporated to the point canister filter output was splashing a lot. Meanwhile my juvie geophagus had grown a lot. Water change and refill to the topbefore bed. Bodies all over in the morning. Water parameters were fine. Necropsies showed no obvious disease. And once Iadded an airstone the deaths stopped.) I do however think it would be next to impossible to do that to a betta. If every single fish *but* mr betta died i would suspect O2 depletion.
Sorry for your loss
But yes, adequate flow in a tank is definitely a necessity.