I'm not sure what system you are looking at, but I bought one about a year ago (off ebay) and it works great. Very easy to put together and install. It was pretty much put together as it was. I think I attached the hoses and connected the input hose to a faucet. I have the unit set up over my washer/dryer and used a "Y" connector to hook up off the water source, one to the washer and one to the RO/DI unit. I don't even use a tank, I simply fill one gallon jugs. I set the timer on my stove so I don't forget. I always set the filling jugs on top of the washer so if I do forget the jug will just over flow and the water will run into the washer. Only did that once.