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Clearing a Cloudy Swimming Pool Water Permanantly

Updated on April 6, 2017
Clearing Cloudy Swimming Pool Water
Clearing Cloudy Swimming Pool Water | Source

Cloudy Pool Water: Causes and Treatment

(Sources of the Information: All the information included in this post are based on knowledge of my profession as a chemical engineer, personal working experience of more than 7 years, and standard rule and regulations by relevant bodies)

Maybe you have a pool party next, and you suddenly realize that your pool water is cloudy: Thank God it is not green.

A cloudy pool water comes a result of three things: Incorrect amount of pool chemicals, faulty pool filter, poor circulation, or environmental factors. Clearing cloudy swimming pool water may not be tedious like clearing a green swimming pool water, which may take several days before seeing any positive result.

Personally, I have more than 7 years experience in swimming pool management. I have a sizable home swimming pool and I manage it on my own.

Basically, here are what causes cloudy pool water and measures that you can take as a pool owner to clear your cloudy pool water; and measures you can take to avoid having a cloudy pool water in the future.

1. Wrong use and Poor Balancing of Pool Chemicals

Swimming pool chemistry is the most difficult part of pool management. Using wrong pool chemicals in the wrong water for a wrong purpose, and incorrect amounts of pool chemicals are the major causes of cloudy and green swimming pool water.

Ideally, without the right tools to check the status of your swimming pool on a regular basis, managing a swimming pool will be a hell of a job even if you are using the right chemicals for the right purpose.

The pH and chlorine levels in a swimming pool are among the major causes of problems in the swimming pool: The pH is not directly associated with cloudy pool water, but it consumes and renders free chlorine ineffective when in wrong balance.

When free chlorine level goes down, it forms combined chlorine (chloramine), which turns water cloudy and is ineffective in killing bacteria and other organisms such as algae.

Besides pH and chlorine, you need to closely watch changes in the level of total alkalinity(TA). TA cause a number of problems in a pool including pH and calcium scaling, and both are highly associated with cloudy pool water: Here is how to lower total alkalinity when it gets out of the recommended range using aeration.

Other substances that bring about cloudy pool water include high levels of accumulated phosphate, bromine, and incorrect balance of stabilizer such as Cyanuric acid used in the swimming pool.

As such, to avoid cloudy or green pool water in the future; you need a regular water testing strategy of all chemicals in the swimming pool.

Precisely, you need an accurate and easy to use test kit if you want chemically balanced pool water. Rather than guessing on amounts of chlorine, pH, TA, calcium, and other important chemicals using several brands of inaccurate test strips, I use LaMotte 2056 ColorQ Pro 7.

This digital pool water test kit will save you lots of time as it is easier to use and very effective for frequent swimming pool water testing purposes: It's able to carry a number of tests; including pH, free chlorine, combined chlorine, total chlorine, Bromine, calcium hardness, total alkalinity, and Cyanuric acid at a glance.

I use this equipment together with pool calculator to get the exact amount of each chemical to add to the pool. Here is a complete review of LaMotte ColorQ Pro 7 digital pool water test kit.

a) Clearing Cloudy Pool Water Caused by Chlorine Problem

In most cases; when water turns cloudy, chlorine is the first pool chemical that needs to be tested and adjusted as recommended since it acts as the main sanitizer.

The recommended chlorine levels should be between 3 ppm, which should be the same as total chlorine or slight below total chlorine.

The wider the range between free and total chlorine; the more combined chlorine (chloramine) is in the pool water.

In a standard pool, combined chlorine should always read below 0.5 ppm or just 0 ppm if possible.

This means you need to be testing chlorine levels on a daily basis and adjusting it as appropriate before chloramine become excess in the pool, causing lots of pool problems.

If you have an outdoor pool, you can use chlorine stabilizer such as Cyanuric acid to prevent chlorine depletion as a result of UV light from direct sunlight.

In any case combined chlorine reads 1 ppm or above, your pool will turn cloudy and unsafe for swimming. If this is the case, then you need to shock your pool immediately.

Such cases are so rare with saltwater swimming pools since chlorine is automatically tested and adjusted with saltwater chlorine generator. Here is how to shock your pool and the best chlorine shock to use in your pool.

b) Watching on pH and Total Alkalinity

Concentration of pH in the pool water affects how all chemicals in the pool function, including chlorine: When pH level goes too high above the normal range, chlorine will become ineffective and we all know the how important chlorine is in the swimming pool.

The correct level of pH in a swimming pool should be between 7.4 ppm and 7.8 ppm, with 7.6 ppm as the most ideal level. To lower pH level, you need to use pH Reducer (pH Minus) such as muriatic acid or sulfuric acid to reduce the concentration to the required levels.

On the other hand, anything below pH of 7.0 ppm is considered to be too low pH, which apart from turning water cloudy, brings about harmful bacteria such as algae thriving in the swimming pool causing a green water.

To control low pH levels in the swimming pool, you need to use pH Increaser (pH Plus) with soda ash to increase the pH levels to the required levels.

Finally, like noted earlier, ensure that total alkalinity is within the required range of 80 ppm and 120 ppm to avoid bringing up pH levels and causing calcium scaling. Here is the right way to balance to lower total alkalinity when it becomes higher.

2. Pool Filtration and Circulation Systems

Poor water circulation system is also a big problem causing cloudy water very often: If your pool water cannot circulate properly, it will become stagnant and this will eventually turn pool water to be cloudy.

To resolve circulation system, ensure than the return fittings (eyeball fittings) are turned to point down enough to enable water at the bottom of the pool circulate properly. However, circulation system will largely depend on how the pool was built.

Another possible cause of cloudy swimming pool water is poor pool filtration system: Whether home or public swimming pool, your pool filter should run 24/7 for the pool water to remain clean all the time. However, for home pools that are not busy, at least 8 -10 hours a day is not bad.

Your pool filter system continuously cleans the water in your swimming pool, and if it does not function properly; the pool water becomes dirty and as a result it becomes cloudy or green.

As such, it is appropriate to check your pool filter to ensure that it functions without any fault: Moreover, large particles are fond of blocking filtration system; especially the Diatomaceous Earth (D.E) and Cartridge pool filters. Consequently, you need to constantly check and remove particles that may be blocking your filter and may cause your pool water to be cloudy in the end.

Ensure that you regularly clean, backwash, or replace the D.E and Cartridge filter medium as appropriate: If you have to replace the whole pool filter system; the best pool filter will depend on a number of factors.

There are basically 3 types of pool filter; DE filter, Cartridge (Paper) filter, and Sand filter. Each of these filters have their pros and cons.

However, efficiency and recommended application should guide you when choosing the best filter for your pool: DE pool filter is the most efficient in filtration, followed by Cartridge and Sand filters respectively.

On the contrary, DE and Cartridge filters are recommended for home pools and may not be the best when it comes to public (apartments or hotels) swimming pools due to their ease of clogging, which may need a frequent replacement of filter medium.

As such, Sand filter is always the best when it comes to public or semi-public swimming pools. Very important to note, sand used in sand filter also gets clogged and becomes ineffective, which may cause your pool water to be cloudy, dirty or green.

Consequently, the sand should be replace after every one year to ensure that your sand filter is effective to avoid pool water contamination.

Here is a detailed reviews and comparisons of pool filters, which can guide you when you need to select a filter for swimming pool.

Which tool do you use to measure and control your pool chemistry?

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3. The Environment around the Pool

The environment around your pool may also be the cause of cloudy swimming pool water. Cloudy weather usually has some cloudy effect in the pool water.

On the other hand, if trees and building s are next to your pool, the surrounding will become dull since direct sun will be blocked.

Large and small particles inside the pool water will also affect the pool water and may become cloudy as a result. You can use nets to remove these foreign particles from the swimming pool.

Algae also causes swimming pool to be cloudy in most cases, to avoid algae and other harmful bacteria forming in the pool, ensure that you control the amounts of pH, chlorine, bromine, phosphate, and other pool sanitizers in your swimming pool.

Cloudy Swimming Pool Water: Causes and Cure


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    • Barack James profile image

      Barack James 3 days ago from Green City in the Sun

      Hi Richard, high levels of Phosphate means your pool is about to turn green since Algae feeds on phosphate. Phosphate remover is not enough. You need to shock your pool using chlorine and maintain the right level of free chlorine all the time.

    • profile image

      Richard 4 days ago

      All the readings on our pool are good.

      Our water has been tested an our phosphate are high. We have added phosphate reducer twice in the last 3 weeks. We have vacuumed an back washed everyday. An our pool is still cloudy.Any suggestions.

    • Barack James profile image

      Barack James 5 months ago from Green City in the Sun

      Don't mind Andrew; you can still clear the cloudiness, just follow the steps illustrated in this page and you are good to go. I don't understand why you put acid into the skimmer but that alone cannot damage or turn your pool cloudy. Cloudiness may be as a result of chlorine PH or Chlorine levels in your pool. Check on the two and make sure they are balanced.

    • profile image

      Andrew 5 months ago

      I put acid sraight into skimmer box now pool has gone cloudy have i damaged the pool

    • Barack James profile image

      Barack James 21 months ago from Green City in the Sun

      Cheryl; from my own experience, I guess you are using Linear-Quat algaecide containg "Alkyl dimethylbenzylammonium chloride", which tends to foam, stop using it: Rather, next time try Poly-Quat 60 algaecide, which has the ingredient "Poly{oxyethylene(dimethyliminio)ethylene(dimethyliminio)ethylene dichloride}", this is a situation of get what you pay for. The foams will eventually breakdown but after about one week; you can use chlorine shock to speed up the algaecide breakdown.

      Also, vinyl and sometimes plaster pools with insufficient calcium tend to foam: If the issue is not the algaecide you are using, try raising Calcium Hardness (CH) levels to at least 100-150 ppm. Hope that helps!

    • profile image

      Cheryl Cheff 21 months ago

      Added algacide to pool and have had white foam on top for 3 days. How do I get rid of it?

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