more nutrient exchange i guess... air doesn't cause algae... it's the air's affect on the water that does... them new algae scrubbers that run on a bubbler that are magnetic.... the air just causes the water to flow through it... it could be the turbulence it causes, maybe the proteins are more condense to feed the algae, maybe the bubbles cause a prismatic affect on the light that the algae loves, maybe a lot of things... but it would sound like more flow to me that would help with the growth... either way, it works...
eace:
