Envii Sludge Klear - Pond Sludge Treatment, Clears Murky Water & Removes Sludge Down to 40F - (Treats Up To 8,000 Gallons) Bacterial treatment removes pond sludge and improves pond health Improves water quality and clarity by breaking up pond sludge that caused murky water Bacteria breaks up pond sludge allowing it to be caught by filters Each tablet contains billions of naturally occurring bacteria that are safe for all fish, pets and wildlife 1 pack contains 6 tablets capable of treating 8,000 gallons