Getting into a regular routine of pool maintenance that keeps your pool water sparkling clear and hygienic should not cause you too many headaches. The most common pool sanitation chemical is chlorine. it is quick acting and persistent. Unfortunately you do have to add a pool shock treatment every other week – more often if the pool is heavily used- to destroy combined chlorine compounds that build up when chlorine acts on nitrogen and ammonia compounds in the water. But overall the process of using chlorine in maintaining safe water is not difficult. Here are some terms and recommended levels to get you started.
- Freely available chlorine (FC) – This is the portion of total chlorine in the pool water that has not reacted with any contaminants and can actively go to work to sanitize the pool. Your goal should be to keep FC in the range of 2.0-4.0 parts per million.
- Combined chlorine (CC) – Also referred to as chloramines, these form when chlorine combines with ammonia and nitrogen containing contaminants such as sweat, urine, oils and skin cells. If the pool water is too high in chloramines it will cause eye irritation and odors. Your goal is to keep CC less than 0.2 ppm. Any higher and you need to add a pool shock treatment.
- Total chlorine (TC) – Yes you’ve guessed it, TC is FC plus CC. The better test kits can measure TC and FC and this means you can get CC reading as well (by subtracting one from the other).
- Most pool owners use sodium hypochlorite liquid, calcium hypochlorite (in granular or tablet form) or lithium hypochlorite. The latter is used if the pool surfaces are susceptible to bleaching. A key part of ensuring that the chlorine is working effectively is to keep a handle on the pH levels of the pool water. Your goal is to keep it between 7.2 and 7.8 as this will indicating that the chlorine is able to work at maximum levels.