A Benchmark in Protein Skimmer Performance & Control The Diablo DCS-300 in-sump protein skimmer offers advanced control and maximum performance filtration for aquariums up to a 500 gallons. All the latest skimmer design innovations can be found on this Diablo DCS model including: - Bubble Diffusing Chamber and Hybrid Cone Body that naturally reduces and stabilizes the foam production; This means less turbulence in the neck area and more contact time for organics to rise and collect - Oversized Air Silencer for quiet operation and airline mount - Large Collection Cup with flow directional guide, drain and unit venting - Precision Control with the easy to turn output flow valve - Power TheDiablo controllable Direct Current “DC” pinwheel skimmer pumps are the latest in variable speed flow technology that allows for refined control, enhanced performance and efficiency. The vast majority of skimmer pumps available to hobbyist are alternating current "AC" pumps (the type of power that comes out of your wall outlet). Direct current pumps have several key advantages over traditional AC pumps. Most notably, you can control the rotational speed of the motor, thus electronically control air and water flow rates into the skimmer.>>> Performance control by a push of a button!!! Enhanced Pump Control This controller allows users to select between six preset speeds indicated by six green LEDs. The controller also features a feed/service button. When pressed, the skimmer pump shuts down and will automatically reactivate after 10 minutes. Press the feed/service button a second time to resume normal operation. Diablo DC pumps feature a true slow startup where the pump slowly ramps up from zero RPM to the full preset speed over a period of approximately 10 seconds. The pump and controller are connected via a waterproof 3-conductor union. The detachable controller will allow for a simple waterproof union.