15 Gallon tank.

[Bob I]

Originally Posted by EmilyB

Rippling across the surface of the water (powerhead), this will not deal with the crud on the surface when you are not skimming,

Interesting point about the surface crud. I at one time thought skimming would cure that. It did NOT. and further reading implied it would not.

The only thing I ever found that would get rid of crud was to simply run an Aquaclear of any size. Even without filter material.

Not to start an argument, but merely reporting what happened to me.