I'm going to give the two stage d.I setup a go rather than buying my water I currently have an 11ltr di in the garage but need another for the final stage.
Would it be better to get a 25 ltr to save on changes or would a 27 be better to allow room for the resin to move? Or stuck with another 11 to match what I already have?
I'm in Essex and my water is around 400ppm and I'm in a second floor flat so an RO is out of the question