Not only is it a natural way to filter your display tank but it is a sanctuary for micro-organisms to flourish and reproduce. The Macro algae used in the refugium will utilize nitrates and phosphates from your water column. These algae's uses these nutrients to grow and thrive. High quality Refugium filter with unequalled value Includes a 1x32 watt Compact Fluorescent Light for the Refugia area First Compartment is 10" x 13.5" to fit most in-sump protein skimmers. 1" threaded inlet and outlet (for external return pump) Has additional 3/4" threaded bulkhead for submersible return pump Rated 135 gallons 3 year warranty Dimensions: 30L x 14"W x 18"H