Healthy Ponds 51117 Aquasphere Pro Biodegradable Pond Treatment 3-Pack, Each Sphere Treats up to 1,000 Gallons Natural bacteria and enzyme blend reduces excess nutrients, sludge and ammonia, resulting in improved water quality and clarity Each sphere treats up to 1,000-gallon Provides 24/7 water conditioning for 30-day Ideal for stock tanks, koi ponds and small ponds Safe for humans, pets, fish, birds and plants