This pH meter is ideal for measuring the pH level in aquariums, aquaculture, beverages, hydroponic, fish hatcheries, food processing, laboratory applications, spas and swimming pools. Simply turn on the pH meter by the “ON-OFF” switch, immerse the pH meter electrode in the solution to be tested, then stir gently and wait for the reading to stabilize. With this pH meter it is just a few simple steps to get a pH reading. Compact, portable pen type, and the simplicity of operation make it a must buy.