Yes its ion exchange so the hardness ions are replaced by salt ions. I was quite disappointed when we first started using it, you should see the state of the kitchen sink (stainless steel). I should have realised that sparkling clean was unlikely. At least the pipes and appliances aren't filling up with permanent hardness though.
We have water butts of sorts, we use those 1000L cubes in a metal cage which various industrial liquids are shipped in. They can be easy to get 2nd hand and I choose ones with the bottom valve intact and link them up so the level any one or all can be dropped by pumping out of one of them.
The A/C water is in bottles at the moment but something more permanent will be sorted eventually. We get loads of it from the heat pump water heater.
