Aquascape Pond and Waterfall Foam Sealant makes it easy to fill joints and gaps between rocks and boulders, maximizing water flow in streams and waterfalls. There is no need for a foam gun with the easy-to-use spray can. The black polyurethane foam blends easily into rocks and gravel for a natural appearance. Ease of application makes it the perfect choice for the beginner or do-it-yourselfer. For the experienced installer, Aquascape Pond and Foam Sealant is convenient and economical for a quick touch-up on any project.