Aquascape Waterfall & Rock Cleaner Professional Grade quickly dissolves debris from waterfalls, streams, and rocks on contact, significantly reducing pond maintenance. Simply sprinkle the treatment directly on the affected area and watch the debris disappear. This treatment will allow you to spend more time enjoying your water feature and less time maintaining it. Waterfall & Rock Cleaner is able to be used at any water temperature, making it an excellent choice for any time of year. The 9-pound container will treat up to 3,650 square feet of surface.