Few things are as frustrating to pool owners as cloudy pool water.
Unfortunately, your pool's water may become cloudy for a variety of reasons. Before you can fix the problem, you need to understand why your pool water became cloudy in the first place -- it's the only way to know which cloudy pool water remedy to use.
How to Fix Cloudy Pool Water
Any of the following problems may lead to cloudy water and, in some cases, more than one problem may be responsible.
Low Chlorine Levels
Begin your search for a cloudy pool water remedy by testing the water with a standard test kit. Low chlorine levels can allow microorganism populations to climb, which not only makes the pool water cloudy, but also makes it hazardous. Add chlorine as indicated by the manufacturer to raise the levels within the desired range.
Additionally, because some organic substances can bind with chlorine and prevent it from disinfecting the water, you can use a pool oxidizer to help free some of the unavailable chlorine.
Problems with pH
Most pool water contains tiny solids that dissolve into and bond with the water. However, if the pH of your water climbs too high, the solids will begin precipitating out of the solution. This means that solids will begin to accumulate in the pool.
The best way to change this is by adding pool acid to lower the pH of your pool. This, combined with proper circulation, will often alleviate the problem. Try to maintain your pool's pH between 7.4 and 7.8, and replace your test kit reagents regularly to make sure you get accurate test results.
Poor Water Filtration
Things like the wind, rain, trees, and swimmers continually add debris to your swimming pool. Your filter tries to remove most of this material, but problems with any part of the filtration system can prevent this from happening properly. The result is cloudy, debris-filled water.
Unfortunately, backwashing your filter or replacing the cartridge as appropriate for your system are the only ways you can address these problems on your own. If poor filtration becomes a chronic problem, your only option is to replace or upgrade the filtration system.
A high-quality pool filter will collect and remove most of the tiny particles in the water, but some particles are too small to be caught by the filter media - they simply pass right through and keep circulating in your pool. If these particles become numerous enough, they can turn your pool water cloudy.
The best way to address this problem is to use a pool clarifier. Pool clarifiers bond with these tiny particles, making them large enough for your filter to collect and remove them. Pool flocculants -- sometimes simply called pool flocs -- perform a similar job, but instead of bonding to the pollutants and then floating into the filter, pool flocs bond to pollutants and then sink to the bottom of the pool. You then need to vacuum the pool to remove the congealed substance.
Poor Water Circulation
No matter how well your filter operates, it cannot keep the water clean without proper circulation. Circulation is what brings the impurities to the filter for removal. Proper circulation also ensures that your pool does not become stagnant and the chemistry of the pool remains uniform.
You need to inspect all parts of your water circulation system to ensure adequate water movement. Be sure that your filter is clean and nothing is blocking any of the pool's intakes or outflows. Ensure that the jets and intakes are aimed so that they create a circular water pattern, and be sure that all depths of the pool are circulating, not just the surface layers.
The filtration system cannot handle all the debris that falls into the water. Some of it falls to the bottom and becomes sediment. Sediment will sit at the bottom of your pool forever unless you remove it by cleaning the pool.
Thorough, regular cleanings are the only way to remove the bulk of sediment. Automatic pool cleaners can help keep the overall sediment level relatively low, but you should still vacuum your pool once per week to avoid problems.
Pool shocking your water weekly is an important part of maintenance, but it can cause the water to become cloudy immediately afterward. This is particularly true of low-priced, economy shock products, but it can occur with premium products as well.
In most cases, shock-induced cloudiness is no cause for concern, as the water will clear up within a few hours. Just keep your filter pumping and keep people out of the pool until the water regains its clarity.
As when you shock a pool, cloudy water often follows algae treatments. Treat this problem the same way you would shock-induced cloudiness, by keeping the pool filter running until the problem resolves. If time does not rectify the situation, clarifiers are often helpful for treating this type of cloudy water.
Many people are under the mistaken impression that cloudy pool water is solely an aesthetic problem. Nothing could be further from the truth -- properly treated pool water is crystal clear. In actuality, cloudy water indicates that at least one portion of your maintenance regimen is flawed, and you must identify why your pool's water is cloudy and take the appropriate steps to fix it.
Always keep in mind that cloudy water may expose swimmers to a variety of pathogens, so you must prohibit swimming and wading in the pool until you have corrected the problem.