This Water Hardness Tes provides a simple, easy to read test to determine the hardness of water. This test allows determination of the need to treat the water to prevent calcium carbonate build up and to monitor the ongoing efficacy of the treatment used. The Tester consists of a roll of Lo Range test paper with a color match chart reading in increments of 0, 5, 10 and 20 gr/gal as calcium carbonate and a wider range roll of test paper with a color match chart reading in 10, 20, 30, 40 and 50 gr/gal of water hardness. Roll Length: 180 inches. Total Range: 0-50 gr/gal.• Test Water Hardness on Contact• 180" of Water Hardness Testing Tape Built in Color Chart to Detect Hardness on the Spot