Crystal Blue Royal Blue Lake & Pond Colorant uses a proprietary formula to enhance your pond or lake with beautiful royal blue color all year long. Clears up muddy ponds. 100% safe for humans, fish, livestock, pets, birds, swimming, potable water and irrigation. Maintain color and clarity for up to 30 days. Helps settle out dissolved solids. 1 gallon treats 1 surface acre, 4 - 6 feet deep.