I've had pressurized CO2 in my 58g for about 3 months now and it has been a huge source of frustration. I had it set initially for about 2-3 bps just to start and then got a HUGE outbreak of BBA. I bumped it up to an unknown amount (I have a drop checker on order) and since then, I've lost two of my rainbows. Neither of them really gasped at the surface but both hung out about 2" below during the entire day and rarely moved and I'd never seen anything like that before.
The BBA is finally beginning to die out and tonight, I saw one of my two remaining rainbows gasping at the surface. Strangely, my hatchets, ram and last rainbow have yet to show any signs of stress except that all of the fish have become less active and seem somewhat sluggish. Is it possible that the CO2 level is too high and it's affecting the fish in different ways? All of the fish used to constantly chase each other around the tank and now some of them hide while others just stay put most of the day. Even my BN pleco has disappeared for days at a time and it was always out and about.
Unfortunately my needle valve is extremely touchy and while it may seem to be set to a reasonable level for an hour, it seems to increase on its own a few hours later. I'm so frustrated and would hate to lose all of the fish but the BBA wasn't much fun either.
Sorry for the long post but I just wondered if anyone thought that the recent deaths are caused by the CO2, as all other parameters are well within normal (0 ppm ammonia, 5ppm nitrates, 0 nitrites). Also, the pressurized CO2 has dropped my Ph to 6.0...don't know if that had anything to do with the casualties either.
Any information would be greatly appreciated. I'm hoping that drop checker gets here from Aquaticmagic soon.