The Seachem Tidal Power Filters are easy to use and adaptable to a variety of aquarium conditions. The Tidal Filters come with several desirable features—including a self-priming pump, surface skimmer, adjustable flow, maintenance alert, self-cleaning impeller, and a filter basket that can hold extra filter media.The fully adjustable Tidal flow regulation adjusts performance to a specific aquarium volume and environment. The Tidal Filter surface skimmer will capture the water from just below the surface, where excreted fish oils accumulate, as well as deeper in the tank removing floating debris. For aquariums from 15 to 110 gallons. Four sizes to choose from: Seachem Tidal 35 Filter, Seachem Tidal 55 Filter, Seachem Tidal 75 Filter, & the Seachem Tidal 110 Filter. We also have packages with the replacement Tidal media. Useful Links: Best Aquarium Filter?Related Products: Seachem Tidal Power Filter Replacement Media I Seachem Tidal Power Filter Replacement Parts.