How to Clear Cloudy Pool Water

It’s an early Saturday morning. You walk out to your new pool, ready to take a well-deserved dip until you notice, it’s a gross and disgusting mess. What happened, and why does the water look so cloudy?

More importantly, how can you fix it and get your pool looking like a commercial quality swimming pool just in time for the weekend?

Cloudy pool water may be a surprise for you, given that chlorine is supposed to keep the water clean, killing off microbes that might collect in a swamp. A cloudy pool indicates something has gone wrong, or that there may be more serious threats out there beyond the usual pool polluting substances.

In this article, we’re going to discuss why pools get cloudy and how to clear the water for a better sparkle and for better health.

What Happened? Reasons for Cloudy Pool Water

Why do pools get cloudy even after you add chlorine? Primarily for two reasons: first, because of over-shocking the water (a beginner’s mistake), and two, because of common debris and other natural contaminants falling inside.

Cloudy swimming pool water happens because of the same issues:

  • Shocking the water too much or too high, which leads to imbalanced chlorine levels
  • High pH and alkalinity
  • High calcium hardness
  • High ammonia levels
  • A clogged or broken filter
  • Algae development
  • Debris, bugs, and microbes

The outdoor environment is naturally destructive to a pool of clear water. Rainwater, bird droppings, twigs and leaves, flying debris, garden debris, algae, bugs, and even the sun can alter the chemistry levels of the pool water.

When you add chemicals and organics to the water, the appearance and properties change. High levels of pH make the pool cloudy, as does high alkalinity, high chlorine, and high calcium hardness.

Not only can these chemical changes occur naturally because of outside elements, but even altering the chemistry yourself can give the water a milky and unattractive appearance.

Contaminants Make Water Cloudy

If the problem is not a chemical one, then a broken pool filter could be the issue. Pool filters run up to ten hours a day to keep the water clean. If it’s on and the water gets stagnant or dirty, experience tells me you’re looking at an obstruction.

According to a 2013 CDC report, water samples collected from 161 public and private filtered swimming pools, showed evidence of “stubbornly resistant human waste.”

The report stated 50 percent of the samples had contaminants, some even containing E.coli. The source of the contamination was, quite disgustingly, fecal matter in the pool.

The most common cause was not the unthinkable act of going in the pool, but rather, swimmers not thoroughly washing before entering the pool. So, how do you make sure those contaminants get removed?

Now that we know the most common reasons for cloudy water, let’s discuss the necessary steps to clear it and keep it clean for the long-term.

Step-by-Step Guide on How to Clear Cloudy Pool Water

Clearing cloudy pool water is a matter of:

  • Cleaning the pool
  • Checking filtration and ensuring all parts are in working order
  • Balancing chlorine levels
  • Adjusting pH and other chemicals like alkaline
  • Clarifying water to get rid of algae and other particles
  • Preventing cloudiness before it happens by doing regular maintenance

Step 1: Shock The Pool Water

Shocking refers to upping the chlorine content to destroy more contaminants like bacteria, algae, and other organics that make the water cloudy. To kill algae, some recommend double or even triple “shocking.”

You don’t add chlorine directly, but use a pool shock like:

Next, determine the amount of water in your pool and then calculate the pool shock volume, which should be 1 pound for 10,000 gallons of water. See the instructions for more specific guidelines.

Step 2: Filter and Vacuum Debris

Next, verify the filter is working and whether or not you must replace the part. Then, turn on for at least eight hours a day regularly. If you keep the pool clean and the chemistry balanced, this standard should be enough to keep the average backyard pool clear and fresh.

The skimmer takes care of the surface so it can’t reach debris accumulating at the bottom. A pool vacuum can help in this regard.

Step 3: Balance Your Pool Chemicals

Once the water is thoroughly clean, test it for alkaline, pH, and chlorine levels using a test kit. You can buy them online or take a sample to the local pool store for analysis.

Adjust chemicals like muriatic acid, while using chlorine stabilizer to protect your current level of chlorine. Keep the recommended chemical balances for swimming pools are as follows:

  • pH: 7.4 – 7.6
  • Chlorine: 1.0 – 3.0 ppm
  • Total Alkalinity: 80 – 120 ppm (use our calculator to help get you into the ideal range)
  • Calcium Hardness: 200 – 400
  • Cyanuric Acid: 25 – 50 ppm
  • Total Dissolved Solids: 500 – 5000 ppm

Step 4: Use a Pool Clarifier or Flocculant to Reduce Pollutants

Clarifiers gather tiny particles that pollute the water and bring them together to make larger particles that a filter can pick up with ease. Pool filters cannot always pick up the smallest bits, so clotting them together makes clean up easier.

Using flocculant chemicals is also a quick way to clear up the water by gathering all the particles and sending them to the bottom of the pool. Instead of the clarifier picking it up, use a manual vacuum or pool pump to vacuum the larger debris up with the setting on “backwash.” Automatic pool cleaners will not pick it up.

Still not sure on the difference between the two? Read my full guide on pool clarifier vs. flocculant.

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Some Final Tips on Keeping Your Pool Water Clear for Good

To keep your pool looking flawless all year round, remember these tips:

  • Deep cleaning can prevent cloudiness from starting, even in the beginning, when the water first loses its “sparkle”
  • You can also keep the water looking fresh by stirring it and skimming for debris or manually using a pool brush to push the particles in
  • Regularly shocking your pool cleaning the filter regularly by backwashing will go a long way in preventing cloudiness
  • You can also anticipate cloudiness by taking a pressure gauge reading and backwashing whenever the pressure reaches 5-7 pounds per square inch above regular readings

Remember, keeping a pool is an art project as much as it is managing hardware. Clean the area regularly. Be aware of the most common threats that change the water’s properties.

Keep up to hygiene codes for family and friends, and use all the latest appliances to keep up constant monitoring and maintenance. If you take the time to keep your pool looking beautiful, it will sparkle and look as clear as glass!

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