not in DC area but we had it before while living in the midwest. We had Culligan water softener system. IIRC had to replenish the system wit big bags of salt every month or so. Everyone visiting said that our water tasted better.

Anonymous wrote:you need a softener not filter

We want to reduce hardness across the house not just for laundry and dishes.

you need a softener not filter

If you have one in your house, is it effective? What brand/installer did you use? Our water is very hard.