The one-dip Biguanide test strip measures Biguanide (0-80 ppm), Alkalinity (0-240 ppm), pH (6.2-9.0) and Total Hardness (0-800 ppm). The formula is designed for stable color development allows adequate time for the user to match very distinct colors along with preventing cross-contamination between pads. Each bottle includes 25 test strips packaged in a waterproof PopTop bottle with a molded desiccant liner, which protects the strips from moisture and UV light.