Q: We went on vacation for a few weeks and came home to a cloudy pool. We have maintained it in the spring and have used it several times already, so why is my pool cloudy?
A: Maintaining a swimming pool in early summer is a good idea to keep the pool in top shape for family fun. Despite the spring maintenance, swimming pools can still become cloudy quickly. Fortunately, there are several easily identifiable reasons and solutions for homeowners asking, “Why is my pool cloudy?” »Broken or clogged filters, growing algae, pH issues and chemical imbalances can make a pool cloudy, and this can happen whether the pool has been heavily used or not.
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There may be low levels of free chlorine.
If your cloudy pool smells of overwhelming chlorine, there may be less free chlorine than there should be and the water is not sanitized. Chlorine pool treatments have more than one type of chlorine that works in tandem to kill microorganisms. If they are out of balance, the water will not be sanitized or clear.
You can use a chlorine test strip to identify if the free chlorine is too low (ideal is 3 ppm). If so, the pool will need shock treatment. For homeowners who use a saltwater chlorine generator, the same applies. Stop the generator while applying manual shock treatment to rebalance the pool before it begins to grow algae.
There may be a problem with the water filter.
Pool filters help prevent debris and particles from lingering in a swimming pool. Filters should run at least 8 hours a day to keep water flowing to collect dirt and debris. If the pool has bottom drains, turn them on to remove any sediment while the filter is operating. Sometimes these filters or valves can clog or wear out. Try removing the filter and cleaning it, then backwashing it until it is clear. Replace filters at least twice a year to keep swimming pools clean and cool.
Minute amounts of algae can make swimming pool water cloudy.
Algae is an unwelcome sight for any pool owner. Algae occur naturally and are found in plant and soil debris. If you catch algae early in its growth, it is possible to eliminate it before it becomes a significant problem. Green algae photosynthesize quickly, especially on sunny days.
Sometimes chlorine treatments can’t keep up, and an algaecide or pool clarifier can target growing algae, although too much can cause foam or copper to build up in the water. Be aware that an algaecide is only effective before a large algae blooms and may not work on black algae. In these cases, call a local pool service professional.
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Very high calcium hardness levels can make the pool water cloudy.
Many outdoor pools have hard water, which contains minerals like calcium and magnesium that leave residue behind. If a pool has a cloudy appearance that simply won’t dissipate, high calcium levels may be the problem. The excess calcium will visibly scale the walls of the pool and likely clog the filter with hard mineral deposits. A clogged filter will not do its job. In this case, the pool will need to be partially drained and filled to maintain the optimal calcium level between 200 and 400 ppm.
The pH of the water can be too low or too high.
Part of regular pool maintenance should include testing the water with pH test strips. Ideally, a swimming pool should have a balanced pH of 7.6. A value less than 7 indicates an acidic pool, but a value greater than 7.8 is too alkaline. A pool measuring at either extreme will likely be cloudy. High pH often indicates excessive calcium deposits, and low pH often indicates more chloramine and less free chlorine. Treat the pool accordingly, based on the pH.
Chemical imbalances can make pool water cloudy.
In some cases, trying to identify which chemical is out of balance can be a challenge you’d rather leave to a pool maintenance company. Chlorine isn’t the only chemical to worry about; there is also bromine, phosphate and cyanuric acid. Pool test kits can help check for a chemical imbalance.
Heavy rain can make the pool water cloudy.
The outdoor pools are at the mercy of the elements of nature. Excessive sunshine affects the quality of the pool water just like heavy rains. If a swimming pool received heavy rainfall, it could make the water cloudy as it diluted the water and caused free chlorine levels to drop. In some cases, too much rain can even push sediment into the pool and overwhelm the filters with debris. Some debris contains phosphorus which promotes algae.
The flora and fauna of the environment can be the culprits.
Insects, birds, and mammals (pets and wild friends) sometimes dive into a pool to cool off. They leave behind dirt, waste and contaminants that can upset the pH balance or clog the filter. Trees drop leaves and pollen which can also cloud the water. A skimmer helps collect debris from the surface, but frequently check chlorine levels in areas where animals, insects, pollen, and debris often congregate in the pool.
Maintaining a swimming pool isn’t always an easy task, but it’s worth enjoying a dip in crystal-clear water. If maintenance becomes overwhelming or if you are embarrassed by pool issues, a professional can help you keep the pool looking its best all summer long.
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