Powerhead 802

[Scavenger]

I have a theory on your bubble bursts that may work.
I have a recently set up 20 gallon and I was only running one 301 power head in addidtion to a ac 150 in it. It wasn't issuing the most of current or breaking the surface much. I too was getting bubble bursts every 15 seconds or so. Also, my algae blooms were more than most people experience in a new tank.

OK now for my theory. Excessive carbon dioxide is a major factor for algae growth. I figured I wasn't getting a good gas exchange and carbon dioxide was building in my tank. I recently added a second 301 and now have great surface churn and tank current. My algae has decreased signigicantly and I have yet to see a bubble burst from my power heads. I figure that the bubble bursts were accually caused by excessive carbon dioxide. This is however just my theory, but I don't have near as much algae and no bubble bursts at all now.

This may be applicable to your tank too. It might be worth a thought.