stupid sand wont stop moving!!!

[kien]

I've never run a wavebox so I can't answer that.. but I do have another suggestion. Try placing small rubble, shells or a higher grain sand just under the powerheads where the piles area. They should be heavy enough to prevent piling up, and there should be enough flow (suction) to pull detrtius out of the rubble so that it doesn't sit. Might have to play around with how large of an area of rubble/shells/high grain sand that you'll need.