These Total Hardness test strips are perfect for service work, classroom demonstrations, or to give to customers for the ability to run diagnostics on their own water from the comfort of their homes. They offer a wide range of detection and are calibrated to be both accurate and sensitive. With their short turn-around time and high accuracy, these Total Hardness test strips offer you time-savings; no more counting drops or waiting for laboratory results, you are in control and can find out exactly where your calcium level is before it becomes a problem.