I've got plenty of air going into the tank. i did a water change about 5hrs ago and they fed ok 1hr later! Zero ammonia and nitrite - i don't understand it!

duanes;922449; said:If your water comes from the tap with ammonia, it means your water provider is using chloramine as a dissinfectant. If your tank is properly cycled, and not overcrowded your benificial bacteria should take care of that small amount.
As for humans, chlorine combined with organic(s) produces trihalomethane, a carcinogen.
Water providers use chloramine(chlorine combined with ammonia) because trihalomethanes are not a byproduct, and makes water safer for human consumption, and keep harmful bacteria from growing in the distribution system. Do not use RO completely in a tank it can adversly effect your fishes ability to osmoregulate, it is also, not that great for human comsumption either.
If your Pbass were wild caught they may have internal paracites, or as others have suggested, need live food and need to be trained to take pellets or dead shrimp.