How to Read Pool Chlorine Levels
Chlorine is added to pool or hot tub water to kill germs and prevent your swimmers from becoming sick. Free chlorine can kill most germs within a few minutes if used properly. To determine your pool’s chlorine levels, dip a test strip in the pool for a few seconds and then match the resulting color of the strip to a chart linked to “parts per million” chlorine levels.
Some pool test kits measure “free chlorine,” while others measure both “free chlorine” and “total chlorine.” There is a difference between “free” and “total” chlorine.