03-24-2007, 07:00 PM
Join Date: Feb 2007
| | Re: Just wiped out a tank of fish
Another reason not to OD with CO2 injection. 15 to 20 pmm should be more than adequate for many tanks. For best performance, the CO2 should be added to the intake of the filter. If the filter stops, then the CO2 level in the tank will also stop due to the lack of water circulation. Too much CO2 will cause a significant drop in pH when working with low KH water. This can kill fish.
If the tank is NOT OVERSTOCKED, then the top surface area of the tank should provide adequate means for the exchange of O2. An experience aquarist will never allow the tank's water chemistry to go hay-wire during a power blackout. Remember, a good tank should not rely on filter and airstone to keep the livestock healthy.
Since you only have 12 fish in a 55 gal tank, O2 depletion should not be an issue. I've kept 40 cardinals, neons, and otos in a 50 gal for 3/4 day without the benefit of filter/pump/airstone.