In-Sump High Output UV Sterilizer - IceCap

UV sterilization works by exposing free-floating microorganisms to germicidal ultraviolet light as water passes through the sterilizer body, disrupting their DNA and rendering them unable to reproduce. The IceCap In-Sump UV Sterilizer brings this capability directly into the sump, where water is already moving through the filtration loop. The result is reduced pathogen load in the water column, improved water clarity, better redox balance, and less strain on the immune systems of fish and corals—without introducing any chemical treatments.

All three wattage options ship as complete plug-and-play systems. The 18W model pairs with a DC-700 pump and is rated for saltwater systems up to 60 gallons or freshwater up to 600 gallons, making it a practical choice for smaller all-in-one setups. The 27W steps up to an EVO 1000 pump with ratings of 140 gallons saltwater and 1,300 gallons freshwater. The 40W uses an EVO 2000 pump and extends coverage to 400 gallons saltwater or 3,000 gallons freshwater. Included hose barb fittings accommodate 1/2", 3/4", and 1" flexible hose, and secure mounting brackets hold the unit in place within the sump without requiring any penetrations or permanent plumbing.

Because UV light only affects microorganisms passing through the sterilizer chamber, it does not disturb the nitrifying bacteria colonizing your live rock, filter media, or substrate. This makes it straightforward to run continuously alongside an established biological filter. Lamp life is rated at 10,000 hours across all models; because UV output degrades before a lamp visibly fails, replacing the lamp on a scheduled basis—typically every 12 months—keeps sterilization effective.

For hobbyists with space in the sump and a preference for minimal external plumbing, this unit fits cleanly into the existing filtration footprint. Those needing higher wattage or a longer dwell time for larger systems may want to compare external inline options such as the Aqua Ultraviolet 57W Classic. Within the IceCap line, the 18W suits smaller reef or freshwater tanks, while the 40W is appropriate for larger mixed reef or fish-only systems where pathogen pressure is a regular concern.