I've got a fairly new softener from Eco-Lindsay, and it hardly uses any salt at all. I've asked the folks how much it SHOULD use, and, since there're variables involved, they will never give me any sort of answer. I have the "hardness" set to 40 (I'm told that the "hardness" digital indicator between 0 and 100 actually is positively correlated with the softness... go figure), and we have three adults in the house. I recall filling the old softener with about 40 pounds of salt in two weeks when we had four adults in the house.
In a month, the salt in the new softener hasn't budged more than a couple inches. There's GOT to be somebody with some gross, order-of-magnitude idea of whether this is normal. (Our water quality has been declining for quite awhile since we moved into the neighborhood -- the Eco-Lindsay folks say there's just a lot more people using water now -- in taste, iron deposits, etc.) This is supposed to be a "high efficiency" unit, but, hey.... cycling every three days should use at least a few pounds, right?
Any even anecdotal data?
Mark