Mark has alot of good stuff there. We used to use soft water for work, but it was not pure enough for what we use and end up using alot more products to make it work great.
There are a few other things you can look for...like the RO system..or DI water. Simple way is to throw on like a carbon filter, then call Culligan to get a set of their tanks that they switch out after X amount of hours. We do this and our local shop charges us $30 or $35 a month.
Otherwise if you want to buy something there this...
http://purerinse.com/ We looked into this and bought one of their small units. Jim and his guys can help you out.