hi GB dont forget about pure freedom, thats were i got my DIY unit from. its very easy to set up , if i can do it you can. i went for the 200gpd day RO ( my TDS is in the 500's) . the RO takes it down to 28 ppm then i have 2 DI units which polish it off to 000ppm. dont get the pole ive never used mine, got a gardiners 27 clx. i got the 250lt tank but i find this is too small now( i drive a combo ). my tank is strapped to the bulkhead, and more recently ive had a catflap fitted to the rear doors for security reason ( i will post a pic ). regards