you could try an in-line scale inhibitor as well, if you have hard water. I put a small one in front of the hw heater and since then the showerheads and other appliances look better at least. We have exceptionally hard water where we live, but my wife has sensitive skin and she hasn't really had the same itchiness that she occasionally had prior to this. Not that this is really designed to be a softener, but it seems to have made a difference for us anyway.
it's mostly to help with preventing buildup in the water heater, tanked or tankless both.
http://www.amazon.com/Aqua-Pure-AP43...VSPZNYG1VA8GEB
We change the canister every 6 months so there is some annual cost with it, but it seems to have been a good buy in our case.