Healthy Ponds 10031 4" Flower Lily with (2) 2,500 Gallon Refills Natural bacteria and enzyme blend reduces excess nutrients, sludge and ammonia, resulting in improved water quality and clarity Treats up to 2,500 gallons Each refill provides 24/7 water conditioning for 30 days Saves time and effort, with no mixing, measuring or mess Safe for humans, pets, fish, birds and plants