Aquascape Prevent for Fountains & Waterfalls XT prevents unsightly fountain conditions to keep fountains looking clean and clear while reducing maintenance. Prevent for Fountains & Waterfalls XT is available in half gallon and gallon options and designed only for use with the Smart Pond Dosing System XT. The treatment uses a special blend of clarifiers to clear and prevent debris and white-scale buildup in the water and on the surface of the fountain, rocks, or gravel. The formulation also works to prevent stains, foam, and other unsightly water conditions. Prevent for Fountains & Waterfalls XT is safe for birds or animals that may drink from the fountain. Prevent for Fountains & Waterfalls XT is not safe for fountains containing fish.