This item ships via a Freight Company Additional Shipping May Be Required Please contact us for details SeaLife Systems introduces our newest line of filter systems, the ReefMaster Pro? Refugium. Refugiums are designed primarily for use on reef tanks but can be used on fish tanks that have adequate biological filtration. Refugiums work on the principal of placing algae and other marine plants in the filter and providing adequate light for them to grow. The algae remove organics, nitrates and other harmful chemicals from the water. As the algae grows, it is harvested and the harmful chemicals are removed from the tank permanently. Deep sand bed keeps nitrate at a safe level. Top mounted input provides more filter positioning options than side mounted inputs. Black refugium walls reduce light scatter and reduce unwanted algae growth in sump area. Micron sock prefiltration produces crystal clear aquarium water. Separate sock and refugium covers simplify sock removal. Algae gate in refugium keeps algae fr