Tonight I acclimated a 3" boesmani rainbow I've had quarantined for a couple weeks from my 10 gallon to my 75 gallon planted tank with co2 injection. I was stupid and wasn't thinking that bigger fish require more oxygen than the smaller ones I have. As soon as I put him in the tank he began gasping at the top of the surface for air. I shut off the co2 and turned off the lights as soon as I realized what was happening. I hooked up the venturi to the powerhead to oxygenate the tank. He seems to be doing fine now. His colors are actually amazing and better than I've ever seen them. I'm a little nervous about him getting ich because he was stressed. I really can't afford an ich outbreak in this tank. What would you do in this situation? Any help would be greatly appreciated.