How long is your reactor, and how long does the airline go down into your reactor?
If you can lengthen the airline in the reactor to let the bubble travel further, it should help.
Or get another piece of 1.5" PVC, and 2 couplers, and lengthen the reactor, and make the bubble travel farther.
I've burped it a couple of times now and the noise comes right back in a couple of minutes.
I would think that if there wasn't enough flow to disolve the CO2 that eventually I'd have an entire reactor full of it, but there seems to be a point where it reaches equilibrium.
I don't have bioballs in there.
I just don't understand what would have changed to make it noisy. I had this setup before I moved and it was completely quiet. It's in the exact same position as before but after the move it's very noisy.
I remember back a while that I did a big cleaning and even removed hoses etc. When I put it all back together, I reversed some of the hoses and started getting air bubbles coming from my water return to the tank. I looked and relooked to try and figure out what was happened. I thought I had an air leak that was being sucked in. Well I finally figured out that my flow was backwards through my reactor.