Those are a little to small world a pair of golden wonders replace the African butterfly fish and add about 8 harlequin rasbora or von rio tetras
I have 2 aquaclear 30s in my 20g tanks. They have blown bubbles for a few months but now seem to have stopped. When I set up my 75g, I added an AquaClear
Your incoming water maybe high in Nitrates, did you test your "new" water??
have you calibrated your test for nitrates? Even the "professional" tests have to be calibrated to be accurate.
The other thing
Your regulator should regulate the pressure.
If pressure is building up to a problematic level there may be other problems.