Aqua Chek salt water test strips are a unique test strip that simplifies an otherwise complicated testing operation in your swimming pool that uses a salt chlorination system. Unlike other water test kits, the Aqua Chek salt test strips will give you a specific reading of the salt level in your swimming pool water. A proper level of salt will ensure your salt generator is able to produce the desired amount of chlorine and keep the water free of contaminants. From a small water sample, this strip allows consumers and pool professionals to measure levels of sodium chloride (salt) with the highest precision in three to four minutes. Easy and accurate, the Aqua Chek salt test strip measures salt levels from 400-7000 ppm. Very easy to use and test, this container comes with complete instructions and 10 strips per container.