Sorry for starting another thread ive asked this before, but im now im armed with new info.... I am moving home this week, and i have just found out i will not be on a meter. I also had a cheeky test of the water and it is 103ppm compared to the 160ppm i have been using So a bit of a result, does anyone know how many litres i would expect to get out of 103ppm with a twin d.i setup? i used that calculator before but cant find it? is 103ppm low enough to get away with twin d.i Also because im not on a meter waste will not be as much as an issue so maybe i would be better off going RO?