Kasco’s AquaRenew Pond and Lake Dye is the simple and effective way to enhance the natural beauty of your pond or lake. This highly concentrated and effective formula is available in blue or dark blue and comes as powder in 4 oz. water soluble (ws) bags. Application is as easy as tossing a bag in the water. Just one bag will treat over 400,000 gallons of water. AquaRenew will tint your water an aesthetically pleasing blue or dark blue and is completely safe for humans, pets, livestock, and fish.