Care to elaborate on that a bit more? I have used co2, the same stuff that is used in planted tanks to euthanize animals. So yes, it will kill..
Really, people use their CO2 to euthanize animals in the water? You mean deliberately or accidental btw?
@Jag, your bottle only released a few pounds worth of CO2 over a decently long period of time. It would only be an issue if your house was sealed up like a bubble. So you're pretty safe.