I have a 100 GPD ro unit that I won a a Ohio Reef meeting several months ago. I am selling this one with all new filters and membranes never used or seen water for $135. It is a 4 stage RO unit. I am selling this and my used unit so I can purchase a large unit. I want a 300 gpd system. So in order to buuy that I need to sell some equipment that I have sitting around.