About pH: pH is a measurement of your body’s electrical balance and helps to regulate several bodily functions. If your pH varies too much it’s difficult for enzymes to function properly, which can lead to illness. For urine & saliva: Using either saliva or urine you can test your pH to determine if your body is too acidic or too alkaline. It is very important to your health, can’t be ignored. For water: It is important to control the pH of water since it can be an indicator of other water problems. This applies in particular to private water supply, ponds, aquaculture and aquariums If the pH value is too high, the disinfectant can not sufficiently exert its effect. If the pH value is too low, metal parts could be corroded. Usage: Open the round plastic case (by pulling the bottom half in black plastic) away from the top half (in clear plastic) Unwrap the roll of litmus paper and insert it back. Make sure the end of the Litmus paper goes through the slot of the black case. Put the clear plastic top back on so that the slot on this one matches the slot on the black bottom. The Litmus paper should now easily fit through both slots so that it can be pulled out of the plastic case.