Thanks everyone. I've got it right at the surface right now and that definitely lessens the loud popping-bubble sounds, it's still quite noisy. I tried stuffing a filter sponge inside the top of the filter tube (where the filter media is house), hoping that would defuse the bubbles into smaller bubbles, but it didn't really work. It really messed up the movement of the filter media, and it didn't really diffuse the bubbles. It was worth a try, lol. I will keep you posted if anything else works!