Ok, I understand it to be a filter method of ridding unwanted dissolved particles and chemical's like chlorine, BUT how does it work. I don't have a system myself and have been using tap(I know, I know, TDS and other stuff), but my fishes are doing fine. I have been looking into getting a good system, but I am wondering if ro/di is a "drip" method of filtration or what. Is there a way that I could hook an ro/di filter up to my kitchen sink and have it filter all the water coming through my faucet? That way I don't have to find a way to store the water(yes, I'm kinda lazy). Just trying to understand how a most likely simple thing works and what I can do with it. Plus it would help justify to the wife about why the money is going out.