The Laguna PT1680 is a UV pond clarifier for ponds of the following size:
The Pond Water Sterilizer Clarifier 55W - 5000 Gallons contains a 55 watt Ultra Violet (UV) lamp. This Laguna UV sterilizer will eliminate green water from your large to extra large sized pond, meaning that it clarifies the water. This PT1680 clarifier has a LED light that indicates when the UV lamp is on. This clear pond water sterilizer comes with 2 universal Click-Fit connectors that fit 3/4, 1, and 1 1 1/4 inch hosing.
The Laguna PT1680 specifications: