My 4x40 RO started producing water at the begining of this year.
I only have about 45psi pressure from the mains supply but I have set it up to about 80% pure- 20%waste.
I fill my 800ltr van tank up from my 1000ltr static tank when I arrive home from work.Turn the outside tap on at the same time to get my ro working, It as a valve and ballcock attached to static I either turn water off before gong to bed or leave it running through the night.
If it is going to freeze, I leave the water running, because I think running water will not Freeze as easily as standing water.
Pleased as punch with mine. I worked out I would have had to buy a bag of resin every 2 weeks if I had gone DI only, thats £2000.00 a year in resin at £80.00 a bag.
I should only use 1 bag of resin a year now, My mates have asked me if I will sell pure water to them. I will have to work out if its worth the hassle.
My system was brand new and I paid £800.00 incl vat for it, ITs on a stainless steel stand which is faced in the same Black Substance that my van tank is made out of. 2 10" pre filters, 4 x 40 RO, 13ltr DI tank full of resin all attached to stand. John guest fittings, Valve and Ballcock fittings for my static tank. It looks the dogs b******s.All I had to do was push hosepipe in, and hosepipe out.
I'm very impressed. Money well spent.
Nel.