i like my spectrapure for the price. sediment filter, carbon filter and ro membrane gets me from 150s tds to 1-4 tds. came with a built in tds meter on the in/out lines. i think i paid around $125 for it and membranes arnt too bad. Mines only 25GPD though. I would deffinetly go bigger if you can afford it. its a pain to hook it up and fill my 5 gallon storage tank...