Calelin 20W Pond UV Light with Timer UV Pond Water Clarifier for 100-1000 Gallon 18FT, IP68 Waterproof Submersible UV-C Lamp for Aquarium, Koi Pond, Pool, Fish Tank, Cold Plunge Algae Control

Built-in Timer for Easier Operation: The included timer control allows you to set a scheduled working time 3H, 6H, 12H, or 24H working cycles with one-button control. It helps manage daily use more conveniently and supports consistent UV-C water treatment for ponds, pools, spas, and large tanks. Help extends the service life. Quick UV-C Dis-infection Designed with dual-tube UV-C technology, this pond UV light helps reduce 99.99% of algae, odor-causing contaminants, and cloudy water for clearer water. Ideal for ponds, koi ponds, swimming pools, cold plunge tubs, spas, and large fish tanks up to 1000 gallons. Weighted Bottom Block for Stable Sinking: The weighted bottom block helps the UV pond light sink by its own weight and stay upright underwater. The self-standing design supports more stable placement and better 360° coverage. 18FT Extra-Long Cable for Flexible Placement: The 18FT power cable makes it easier to place the UV light deeper into ponds, pools, cold plunge tubs, or large fish tanks. Ideal for both indoor and outdoor water features where extra reach and flexible positioning are needed. IP68 Waterproof & High-Transparency Quartz Glass: Built for reliable underwater use with multi-level sealing, thickened protective end covers, and a durable IP68 waterproof structure. The high-transparency quartz glass tube allows UV-C light to transmit for stable performance.