Controls growth of algae and submerged weeds by coloring the water and absorbing sunlight needed for their survival.
Helps prevent algae blooms.
Completely safe for fish. The overgrowth of algae and aquatic weeds in garden ponds, as well as in many other man-made aquatic systems, will compromise their attractiveness and their general health. Pond Care Algae Blocker controls algae, underwater weeds, and undesirable submerged plant life in ornamental and recreational closed-system ponds. This product colors the water and absorbs natural sunlight, thereby inhibiting growth of algae and aquatic weeds, and effectively preventing algae blooms. Algae Blocker turns water into an attractive blue-green, and will last up to four months in ponds not filtered with activated carbon .