Why Is My Pool or Spa Water Cloudy or Not Clear?
There may be several reasons for your pool or hot tub water not being clear.
First, check the pH value of your water with a digital pH meter. The pH value should ideally be between 7.2pH and 7.4pH and certainly not less than 7.0pH or above 7.6pH. If pH is outside the range of 7.2 to 7.4 then correct the value with pH minus or pH plus. Next, check the alkalinity of the water using an electronic photometer. The alkalinity should ideally be between 80 to 120mg/L.
Check the free chlorine value with a digital photometer. The ideal free chlorine value in an outdoor swimming pool is between 0.5 and 3.0 mg / l, in an indoor pool between 0.5 and 1.5 mg / l and in a spa between 1.0 and 3.0 mg / l.
Check the concentration of cyanuric acid in the water. This is important because Free chlorine is no longer active if the concentration of cyanuric acid is greater than 70 mg. Cyanuric acid comes from chlorine tablets and stabilised chlorine granulates/powders and prolonged use can cause chlorine lock which means the chlorine is unable to act as a sanitiser even though it’s present in your pool water.
Check the calcium hardness of your water. Too much lime in your water causes turbidity which means it makes the water appear cloudy. The calcium hardness should ideally be between 100 and 200 mg/l CaCO3.
Check the iron content of your water. Too much iron in your water causes brown spots , clouding or brown water. The maximum concentration of iron in a bath is 0.2 mg / l and can be measured with the HI-721 . Preferably, do not use well water to fill your pool or spa!
Check the concentration of nitrates (<50 mg / l) and phosphates (<2.5 mg / l) in your water ( HI-83326 ). These substances come from fertilisers (eg lawn) that may end up in your bath. Nitrates and phosphates are nutrients for algae that in turn cause green water.
Check the operation of your filter installation. Clean the filter regularly by, for example, rewinding (backwash) every week. After all, the water treatment in a swimming pool depends for 50% on the filtration. If many small particles are present in the water, you can increase the efficiency of the filter by using a flocculant or flocculant. Be careful, if you use too much flocculant, you may get cloudy (milky) water.