Hwarang":2wdtsscz said:Yea it just works by sluicing the protein off the top of the water. One way this affects your nano is that the water in your "sump" or whatever/wherever the volume is behind/below the surface skimmer, it evaps quick. When I built one on my nanocube 12, i had to be more aggressive about top offs. It's great for a small tank tho, as actual skimming isn't usually appropriate.