Powerhead "Night Mode"

[fkshiu]

Originally Posted by Slick Fork

Also, as far as gas exchange goes I would be willing to bet that the skimmer and/or drop into the sump provides the vast majority of gas exchange in the average reef system. JMHO

+1

The surface agitation provided by the zillions of tiny bubbles in a skimmer probably greatly exceeds any rippling at the surface of a tank.