Healthy Ponds 51118 Aquasphere Pro Biodegradable Pond Treatment 2-Pack, Each Sphere Treats up to 12,500 Gallons Natural bacteria and enzyme blend reduces excess nutrients, sludge and ammonia, resulting in improved water quality and clarity Each sphere treats up to 12,500 gallons Provides 24/7 water conditioning for 30 days Safe for humans, pets, fish, birds and plants