Healthy Ponds 52012 Pond Water Colorant, Reflection (Black), 5 Ounce Water Soluble Bag, Treats up to 500,000 Gallons Pond water colorants are essential once water clarity has been achieved using healthy ponds products Shades pond and limits sunlight penetration, reducing weeds and algae; within 24 hours pond will take on a beautiful appearance that reflects the sky Safe for fish, plants, pets and humans; made from certified food quality dyes 5-Ounce water soluble bag treats up to 500,000 gallons Simply toss water soluble bag into the water from the shore