if your using tap water, stop! anybody that is trying to grow hydro, or is growing hydro, should be using a ro filter for their water. you can pick one up off ebay that will treat fifty to sixty gallons a day for about seventy dollars shipped. you can almost solve any problems that you will have with your water supply by using a ro system. you can't imagine how much an ro system will improve your grow and your success until you try one!:thumbsup: