Refugiums are one of the most efficient ways of filtration in saltwater aquaria today. 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. Picture Notes: Model 45 pictured with optional equipment. RG-45 Specifications: • High quality cast acrylic refugium filter with unequalled value • Includes a 2x32 watt Compact Fluorescent Light for the Refugia area • First Compartment is 12" x 15.5" x 12" Deep to fit in-sump protein skimmers. • 2 x 1" threaded inlets and 1 x outlet (for external return pump) • Rated for tanks up to 225 gallons • 3 year warranty • Dimensions: 36L x 16"W x 18"H