The Mighty Mite D.I. is a complete R.O.D.I. (Reverse Osmosis) reef water system designed for those on a budget. Featuring three stages of filtration, this system is ideal for Reefkeepers with a fifty gallon or smaller tank. This compact system can be taken anywhere. You can purify water on the move. The Mighty Mite can be used on city tap water or well water, as it purifies water completely through a Reverse Osmosis membrane. Depending upon water temperature and pressure, this unit can deliver between 20 and 50 gallons for pure R.O.D.I. water a day. That's 1 to 2 gallons per hour. You will understand how effective R.O. membranes are when you see just how small a trickle of water is made. The water may trickle but it is still one to two gallons per hour. The pre-filters, though small, remove sediment, particles, and chlorine, just like the pre-filters in a full size R.O. system. This unit is designed with the small user in mind. Say you need one gallon of top off every day, this is the unit for you. The Mighty Mite weighs just seven pounds and is only 15 inches long, seven inches tall, and six inches deep. The unit comes complete with a full size NSF certified in-line sediment filter, a full size in-line GAC (Granulated Activated Carbon) filter, and a TFC (Thin Film Composite) RO membrane & a full size horonzontal DI. Also included are a faucet diverter valve, preset flow control, tubing, and an illustrated instruction manual. Our quick connect push-in fittings, truly make this system plug-n-play! Awesome -0- TDS water easy and affordable.