Tried it once and it was a disaster. If the substrate is shallow the sand all blows to the center of the tank. Too thick and the sand packs up under the plate and stagnates. I tried pond pads between the sand and UGF plates. Worked OK but, I was spending way too much time scooping sand to keep the pads covered. After 6 months of fighting a losing battle, I ripped the UGF out of the tank.