too much co2 HELP!!!

[Margaret Peters]

I've had a co2 system for about a yr. No problem. Lost power for a couple minutes which miust have reset my CO2. I woke up this AM to dying fish!! I did a 15 gal water change on a 50 gal tank and add a air stone . What should I do? (obviously I turned off the co2)

Margaret

[NetMax]

You've basically done it.  A powerful airstone should clear it in about 30 minutes, and a partial water change will knock the level down.  I assume the fish were all on the surface gasping. Gaseous imbalances are usually hard on the bottom-dwellers, so make sure you're getting good circulation to the bottom.  Turning off the lights would normally help them calm down, but a planted tank releases CO2 in the dark : O  - so don't turn off the lights ; ) 

NetMax