Tetra GreenFree UV Clarifiers provide permanent control of suspended algae which cause green water. Removes heavy algae blooms in most ponds within 5 days. Helps maintain beautiful water clarity while reducing pond maintenance. These units are compact, durable, easy to install and energy efficient. 5 Watts Maximum Flow 330 gph Inlet and Outlet Size 1/2"-3/4" Weatherproof power cable Info from EPonds