Highly durable PVC sumps dedicated for all marine aquariums. These designed by experienced aquarists sumps ensure the most efficient filtration to make corals thrive and grow healthily. Cascading chambers combined with quality combs provide perfect conditions for dynamic, but still ultra silent water-flow. Filtration socks chamber allows placing two socks (included in set) with noise supressing caps or replacing them with media reactors. filtration socks compartment – replaceable with media reactors RO water chamber for auto top off system water level marks to provide easy skimmer regulation silent water-flow guaranteed by quality combs scratch-resistant, durable materials