OASE CrystalSkimInnovative Surface Skimming OASE CrystalSkim 600 quickly and effectively frees the aquarium surface of biofilm, floating plant debris and substances For a Heathly Aquarium Environment CrystalSkim eliminates any biofilm from the water's surface. Removing biofilm is important for proper oxygen flow in the aquarium Catches the Finest Debris Designed to catch even the finest plant debris that are almost impossible to remove with a net Individually