Cloudy or milky pool water: causes and solutions

A cloudy or milky pool water is one of the most frequent problems encountered by pool owners. When the water loses its transparency and becomes whitish, it generally means that very fine particles are suspended in the water or that the chemical balance is disturbed. Fortunately, this problem can be corrected quickly with a good diagnosis.

Why is my pool water getting cloudy?

Several factors can cause milky water in a pool.

1. Insufficient filtration

Filtration is the primary cleaning system for the pool. If the pump does not run long enough or if the filter is clogged, particles remain in the water.

Possible causes:

• Filtration time too short

• Dirty or saturated sand filter

• Worn filter cartridge

• Undersized or defective pump

2. Chemical imbalance of the water

Poor chemical balance can prevent products from working correctly.

Parameters to check:

• pH too high or too low

• Alkalinity poorly balanced

• Lack of free chlorine

• Stabilizer too high

When these values are out of spec, particles are no longer properly removed, and the water becomes cloudy.

3. Fine particles in suspension

Dust, pollen, organic residues, or poorly dissolved chemicals can make the water whitish.

This often happens:

• after a shock treatment

• after heavy rain

• in spring when opening the pool

4. Beginning of algae proliferation

Slightly cloudy water can also be the first sign of algae appearance. If nothing is done quickly, the water can turn green.

How to clarify cloudy pool water

Here are the recommended steps to get clear water again:

1. Test the water

Start by analyzing the parameters:

• pH: 7.2 to 7.6

• Alkalinity: 80 to 120 ppm

• Free chlorine: 1 to 3 ppm

Adjust products if necessary.

Test strips are a good indicator or visit a store for a more precise test.

2. Clean and check filtration

• Perform a backwash if you have a sand filter

• Clean the cartridges

• Run the filtration 24 hours continuously

3. Perform a shock treatment

A shock chlorine eliminates bacteria and organic matter that cloud the water.

4. Use a clarifier or flocculant

A pool clarifier groups micro-particles so that the filter can capture them more easily.

How to prevent cloudy water

To keep the water clear all season:

• Test the water 1 to 2 times a week

• Maintain a good filtration duration

• Clean the filter regularly

• Perform a shock treatment after heavy swimming or rain

Need help with your pool water?

At Piscines Geyser, we offer water analysis and the necessary products to quickly restore clear and healthy water.

Whether it's for a clarifier, shock treatment, or a filtration problem, our team can help you diagnose the situation and propose the best solution.