The comments about the high iron well on the booster pump thread brought this to mind for me. We have a lot of calcium in our water supplies in this area. Most city water isn't as bad but I've got a couple of customers with private wells where the calcium is terrible and it builds up on the glass tile in the pool, the landscape lights, etc., etc. Other than a water softener, is there some economical way to remove calcium from the water on a large scale? These are 5 acre properties with 36 or so zones on each plus the makeup line for the pool (which has a TON of glass tile work in it) and makeup lines for 3 water features. The calcium causes problems in all of these places so if it can be removed, it would be nice.