Can CO2 kill good bacteria?

[Gatorguy]

Does anybody know if injecting CO2 before the canister filter will have a negative effect (i.e. kill it) on the good bacteria that should be growing in the filter? Do you have any online sources that I can read that says yea or nea??

I never thought it would be a problem, but after I learned how much it eats up air tubing, and given my current massive problem (http://www.aquariacentral.com/forums/showthread.php?t=83007)
I got to wondering.

[reiverix]

The bacteria in your filter rely on oxygen. As long as they have a good supply of O2 then injecting CO2 will not have any negative effects. Obviously you can inject too much CO2 but your fish will let you know about that.

[Gatorguy]

Ok. Does anybody know the pH at which the "good" bacteria will suffer? Is it the actual pH or just a relatively sudden pH "shift"? Surely the bacteria is fine at 6.6ish, right?

[reiverix]

It's fine. My pH is as low as yours after injection.