I find it easiest to take some 5-gallon jugs to the vending machines outside the grocery store to get RO water. I cut it with out local hard tap water. I did look into an RO system, but we just don't really have the space for one at out place, and I decided to go with mostly hard water tanks. Accepting the water where I live as hard, but I did end up with happier fish, and then they made me happy, too
Water Store... Not in the Midwest. Must be a California thing.
BTW - I still refuse to pay more for water in little bottles than I would pay for gasoline. Crazy what we pay for a bottle of water to drink. I still fill my own from the tap... it is filtered though. I am a little spoiled.