Difficult Water: Will require an ion Trade water softener or nanofiltration stage to remove the hardness salts through the water. Sediment filter will likely not clear away any hardness because the magnesium and calcium salts are in Alternative. Magnetic, electrical conditioners or some other worthless gadgets are not encouraged. http://ricardoyxkxn.total-blog.com/domestic-water-filters-an-overview-23696104