Maximize water flow in streams and waterfalls with Aquascape Professional Black Waterfall Foam. This easy-to-use foam effectively fills joints and gaps between rocks and boulders, quickly drying and lasting for extended periods. Designed with a specially-sealed can, it minimizes waste while providing optimal foam yield. Blending seamlessly into rocks and gravel, the black polyurethane foam creates a natural appearance. Combine with the Aquascape Professional Foam Gun Applicator for best results.