Obviously, some folks use this option. I would have two concerns with a solenoid in the configuration:
- the instructions with my RO/DI unit states that "It is recommended that at least 2 gallons of purified water be discarded before collecting purified water for use. If the unit is not used for several days, run the system for at least 15 minutes before collecting water." This was desribed on another post by YBeNormal @ Mar 22 2008, 04:13 PM with a link to http://www.airwaterice.com/category/.z.merlin/ and see "TDS Creep"
- fear of a failure resulting in (1) turning a reef tank into a "fresh" water tank and (2) major water damage.
I like the idea of a top off container with a limitied capacity (in my case case, a 5 gal but If I had the space under my tank, I would have gone with a 10 gal.)
I'm very please with the autotopoff.com brand. Here is my implementation - http://www.wamas.org/forums/index.php?show...mp;#entry177364