Good RO/DI I dont need alot of GPH (40B)

Talk to the hundreds of reefers who have bought them, most can't tell if its new or refurbished plus its only the housings that are used, all the internals are new.
PurelyH2o is one of my recommended vendors and the Optima Vision is one I see often. You would laos need a handheld TDS meter for another $30 from them.
Another to consider is the Buckeye Field Supply BFS-161 75 GPD Premium which does come with the TDS meter has a little better carbon block than the Optima and a capillary tube flow restrictor similar to the Spectrapure. Neither has the 0.5 micron absolute rated prefilter the Spectrapure has, does not have a treated and tested high rejection rate RO membrane and neither custom blends their DI resins in house so the Spectrapure is still the better value hands down.