Cloudy-looking swimming pools are definitely a turnoff for pool owners. The expectation when using a pool is that its water will be crystal clear. Some pool owners might suspect that too much chlorine added to their pool has made their water cloudy. Typically, though, too much chlorine in a swimming pool never makes water cloudy unless a particular chlorine is used in pools with water that's already chemically imbalanced.
One exception exists to the rule that no amount of chlorine added to a swimming pool will cause pools to become cloudy. The calcium hypochlorite form of pool chlorine can make a pool cloudy under certain circumstances. If you add calcium hypochlorite to your pool and the water is too hard, cloudiness will develop. Water in a swimming pool with a calcium hardness level above 200 parts per million (ppm) is considered too hard to support any added calcium.
Pool owners using calcium hypochlorite to sanitize their pools need to ensure their water stays soft enough. As calcium hypochlorite is added to a pool, it will raise the pool's pH as well as its total alkalinity (TA). Elevated pH and TA in a swimming pool can quickly change a pool's water from soft to hard. Pool owners can avoid hard water issues that lead to pool cloudiness by keeping pH between 7.4 and 7.6 and TA at 80 to 150 ppm.
Once a swimming pool in which calcium hypochlorite is used as the sanitizer becomes cloudy, you'll need to eliminate that cloudiness. The best thing to do in a pool that's cloudy after adding calcium hypchlorite is to stop using that specific chlorine type. Other pool chlorine varieties beside calcium hypchlorite are available that pool owners can use as sanitizers, including sodium hypchlorite liquid pool chlorine. Using a calcium sequestering agent to lower pool calcium levels and clear up cloudy water is recommended.
Literally dozens of reasons account for why a swimming pool's water becomes cloudy, and the number one reason has to do with inconsistent chlorine disinfection. Pool owners pressed for time or just being neglectful will fail to add enough chlorine to a swimming pool often enough. When inconsistent chlorine sanitation of a swimming pool occurs, the first sign of trouble is often pool cloudiness. Sadly, pool owners tend to overcompensate for pool cloudiness by then adding too much chlorine too quickly.
Swimming pool chlorine levels should be at 2 ppm. If pH rises above 7.8, take steps to lower it using muriatic acid (MA) according to direction. When pool pH declines below 7.2, start increasing it. Raise pool pH by adding sodium carbonate at 1 lb. per 20,000 gallons. Pool TA is also lowered by using MA. You can raise swimming pool TA by 10 ppm increments by adding sodium bicarbonate at 2.8 lbs. per 10,000 gallons.