Sorry to hear of your troubles.

I've four of these reactor running and on each just used the same tubing as you did. Hole drilled same size as tubing and glued into place with PVC cement. Pre-fit the tubing into position, lift up about 3/16" apply PVC glue and push back down 3/16" with a slight twist. Locks up immediately and good to go. The tubing should fit snug while pre-fitting. If not the hole is too big and must start over or find bigger tubing. A word to the wise , If you build one of these reactors, build the top portion with the airline tubing before gluing to the 2" PVC (especially the clear PVC). That way if there is a problem with the air lines you don't waste the the 2" PVC.