What tool is commonly used to measure the pH level in pool water?

The pH test kit or meter is the tool specifically designed to measure the pH level in pool water. pH is a crucial parameter in pool maintenance as it indicates the acidity or alkalinity of the water. Maintaining the correct pH level, usually between 7.2 and 7.8, is essential for ensuring swimmer comfort, effective sanitation, and overall water quality.

A pH test kit typically includes reagents that change color based on the pH level, while a pH meter provides a digital reading for more precise measurements. This accuracy is important for proper dosing of chemicals, ensuring that the water is safe and comfortable for swimmers.

Other options like a chlorine test kit, thermometer, and water filter serve different purposes in pool maintenance. The chlorine test kit is specifically for measuring chlorine levels, which is important for assessing the pool's sanitization level. A thermometer is used to check water temperature, impacting comfort but not pH, and a water filter serves to clean the water but does not measure any chemical properties. Thus, the pH test kit or meter is the appropriate tool for measuring pH levels in pool water.