In a message dated 5/2/98 6:26:36 PM EST, Lcrabo@aol.com writes: << I was wondering what test kits people are using to measure hardness? >> I use the Wardley's Hardness test kit. It has enough stuff to break down the difference between general hardness and Calcium hardness, with simple instructions to interpolate other values. It gives readings in ppm, at increments of 10 or 20 ppm, depending on the degree of acuracy and how much of the included chemicals you want to use. But it is a bit spendy at $20. Bob Dixon