Pool water can sometimes become cloudy. There are several possible causes, and in all cases, the cloudy water can be fixed. We will see how to clean cloudy pool water quickly and easily.

If the water is cloudy and green, it is probably algae. See here the method to clean green water in the pool.

We will see the 4 leading causes that make pool water cloudy and the solutions to fix it.

1. A filtration problem

The first cause is a problem with the pool filter. Pool filtration helps clean small debris from the water. With a filtration problem, residues are not removed and remain suspended, making the pool water cloudy.

• The filter is clogged. Clean the pool filter. With a sand filter, it is enough to do a backwash.
• The skimmer or pre-filters are clogged. The filter pump has a pre-filter to remove large debris like leaves. You may also be using skimmer pre-filters. If they are obstructed, they prevent the filtration from working correctly.
• The filter is worn. The filter sand should be replaced approximately every 5 years. Beyond that, it no longer filters well enough. Recycled glass, zeolite, diatom, or cartridge filters have separate lifespans.
• Filtration time is too short. Filtration is not spinning enough to clean cloudy water properly. Constantly adjust the filtration time according to the water temperature. (See here how to determine the pool filtration time (Coming Soon))
• The pump is damaged. Sometimes it’s the pump that has the problem. It works only partially, if at all. As a result, filtration no longer plays its role. Check that the motor is running, the water is circulating and ejects normally at the discharge nozzles.

2. A problem with disinfectant, chlorine

When there is a lack of disinfectant, a lack of chlorine, microorganisms can proliferate. These microorganisms can make pool water cloudy.

To verify the diagnosis, check the level of disinfectant (chlorine, bromine) in the pool, the pH level, as well as the level of stabilizer. If the pool lacks sanitizer, this is likely the cause of the cloudy water.

• Chlorine or salt-water pool: the stabilizer must not be too high. Otherwise, it will make the chlorine completely inactive. The pH should also not be too high (>7.8) because a high pH makes chlorine ineffective.
• Bromine pool: the pH should not be too low. Bromine is inactive when the pH is too low.

To fix cloudy pool water in this situation, you must first balance the water: alkalinity, pH, stabilizer, and sanitizer. Then, you shock the pool with chlorine to eliminate all the microorganisms.

Pool water imbalance makes the water cloudy

Another possible reason for cloudy water is a simple water imbalance. In these cases, it is enough to find the balance so that the water becomes translucent.

• Alkalinity (TA) high. When the TA is too high, the water can become cloudy by precipitating limestone. Lower the TA with acid.
• High pH. In the same way as the TAC, the high pH precipitates limestone. Use one of 6 ways to lower the pH.
• Hardness (TH) high. When pool water is too hard, it can quickly become cloudy due to limescale. It is tricky to get rid of too-hard water. If possible, replace some of the water with less hard water.

Other external sources

Elements outside the pool can make it cloudy. For example, dust or pollen.

Algae grow when water is poorly disinfected or poorly balanced. Algae makes pool water cloudy quickly. See here how to clean green water in the pool.

A storm. After a storm, the pool may be found cloudy. The storm can quickly bring a lot of micro-debris into the pool, which can either unbalance the water or require a lot of disinfection. To clean with the water, you must follow points 2 and 3 concerning water that lacks disinfectant or unbalanced water.

Is it dangerous to swim in a cloudy water pool?

You should not swim when the pool water is cloudy. If the water is not translucent and blue, you should not swim. Similarly, if the water is not balanced (pH, stabilizer, alkalinity, and disinfectant such as chlorine), you should not swim.

When the water is cloudy, there is probably a problem in the pool. It is impossible to know whether this problem is dangerous for humans or not, whether it is harmless bacteria or pathogenic bacteria. This is why you cannot swim in cloudy water.