Laguna"s 28-watt UV Sterilizer/Clarifier helps create beneficial water conditions for fish and plants and is guaranteed to eliminate green water in medium to large ponds. The unit features a unique spiral chamber that allows extended water exposure to UV rays, increasing clarifying efficiency by up to 50-percent. Two universal Click-Fit connectors allow connections to 19, 25, or 32 mm (3/4, 1, or 1-1/4 inch) hosing, making in-line pond installation a snap. The unit also has an LED light that indicates when the UV lamp is on. It can be mounted horizontally or vertically (mounting brackets provided). The Laguna 28-watt UV Sterilizer/Clarifier is covered by a 3-year warranty, and is EPA registered.