hmm

I couldn't tell you for sure but here I my only thoughts... Did you clean the airstone? My old airstone got very dirty and wasn't producing very many bubbles at all, then I put new ones on and then it was much better.... as far as bubbles staying on the surface of the water, my only thought is there's something in the water. It shouldn't do that with just plain water. If there was ANY soap residue it could do that, I've also seen that happen with certain meds... Are you using any medications or anything right now? Those are the only thoughts I have, maybe someone else has a better idea...