it will be a small greenhouse...unsure of the actual size, we are still in the discussion phase. most likely 8 x 15 ish of a leanto design. i know we will need evap cooling out there (can that be tap water?) i dont think the water usage will be excessive....
If your tap water is heavily mineral-laden, then the evaporative medium will get encrusted pretty fact, but there are additives that can help with that.
The Spectrapure systems use standard filters and membranes, so that was a smart move.
FYI, noy t long ago I became a reseller of systems, replacement parts and components, so if you need something, I can probably get you a pretty good price.