Level Loc. I have them on two of my tanks.No pumps no water storage just hook it up to your RO unit and forget about it. Here`s a vid. http://www.youtube.com/watch?v=3OceY9uOKk4
i use tunze osmolator..pretty expensive though if you could find one used that would be good... and i also use Double float switch from autotopoff.com.. been working well and is inexpensive