Firstly, I would like to say hello to all, great website! My query is, I changed over to WFB about six weeks ago, 350 gpd RO, 11 litre RI vessel as I live in a hard water area. Typical reading hovers around 300. My concern is with water wastage, presently on a meter. It typically takes nigh on five or six hour s to produce just 75 litres. Anyway, a fellow windie changed over about the same time as myself and was advised to only use an RI vessel? He uses about 75 to 100 litres a day and has not yet had to change his resin? Could this be possible, how long or how much water could you reasonably expect from an 11 litre vessel? I'm tempted to go that route but obviously don't want to be encountering water quality problems and expense. Your advice would be appreciated. I did think about pumping the waste water back through the RO but was told it wasn't worth it, diminishing returns and all that?