Aqueon ProFlex Modular Sump Filtration SystemsAqueon ProFlex Modular Sump Filtration Systems keep things flexible by offering three completely different setups. The revolutionary sump filtration system can be set up as a refugium, wet/dry or berlin filtration system (BioMedia kit sold separately for wet/dry set up). With aesthetically appealing, clean-line designs, all ProFlex models are manufactured using extremely durable materials, and include a lifetime warranty against leaks. As water enters the ProFlex, it flows through a revolutionary bubble diffuser chamber where bubbles are expelled, significantly reducing noise. After water flows through the bubble chamber, it flows through two 200 micron filter socks to remove large particulates.Refugium - Add a refugium light to create a thriving refugium for your reef aquarium. Live rock and certain plants/algae help control excess nutrients that may hinder the growth of corals in the main aquarium.Wet/Dry - Using the BioMedia Accessory Pack (sold separately), turn the ProFlex into a traditional wet/dry trickle filter. Great for use in freshwater and fish-only saltwater applications to provide advanced biological filtration for a heavy fish load.Berlin - Ideal for reef applications where utilization of a large protein skimmer is imperative. The expansive sump chambers allow for placement of a large protein skimmer and a constant water level.Please Note: For undrilled aquariums compatible sized pump, return line and siphon overflow system are needed. ProFlex Hang-On Overflow kit sold separately.