Submersible Refills, Set of 4

These submersible pond-cleaning refills use naturally occurring, beneficial bacteria and enzymes to remove the source of pond problems by breaking down organic waste and reducing excess nutrients present in the water. Refills fit the Submersible Dispenser Treats ponds from 300 to 2, 500 gallons Each refill lasts 30 days Pack of four refills Each is 3" x 3-1/2" Proprietary blend of beneficial bacteria Designed to work in water temperatures of 50° F or warmer