Cloudy Pool Water: Causes and Cures

In this article I go over some of the most common causes of cloudy pool water. There are only a handful of common reasons why your pool water will become cloudy.  Once the problem is corrected the pool water will return to a clear state within a matter of a few days.

This video is my most popular one on YouTube to date:

I am often asked if a clarifier is needed and in most cases you won't need one. I use them very sparingly on my route and will add it when a customer is having a party or if I need to clear the pool up quickly for an event.  I know pool stores push this product a lot and they do work if you need to clear it up quickly. Sometimes if you have a sand filter a clarifier will help clump the particles together and allow for better filtration.

Cloudy Pool Water: Causes & Cures

This video covers some of the most common causes of cloudy pool water. There are only a handful of common reasons why your pool water will become cloudy.  Once the problem is corrected the pool water will return to a clear state within a matter of a few days.

I am often asked if a clarifier is needed and in most cases you won't need one. I use them very sparingly on my route and will add it when a customer is having a party or if I need to clear the pool up quickly for an event.  I know pool stores push this product a lot and they do work if you need to clear it up quickly. Sometimes if you have a sand filter a clarifier will help clump the particles together and allow for better filtration.

#1 Cause:  No chlorine in the pool. Seems like a simple thing but it happens all the time. If you get busy and forget to check the pool, unusually hot weather, heavy rain or a pool party all can zero out your chlorine level.

Solution: Simply bringing the level of chlorine up to 10 ppm in your pool will reverse the cloudy water - known as "Shocking the pool." Also run your pool for a longer time to help speed up the process.

#2 Cause: Combined Chlorine. Ever smell a chemical like smell at a hotel or the local YMCA? Chlorine has no odor and what you are smelling is Combined Chlorine. Chloramines are what is now in the water and not only do you get an ammonia smell but the water will be cloudy.

Solution: Raising the chlorine to 10 ppm will cure this. Sometimes you will need to raise it to 20 ppm, basically super chlorinate the pool to kill the Ammonia that has formed in the water.

#3 Cause: Not running the pool long enough. You need at least one cycle of water through your pool each day. One cycle is all the pool water going through the pool filter and then back into the pool. If the chlorine is fine but the water is cloudy chances are you are not running the pool long enough.

Solution: Set your pool to run longer.

#4 Cause: A filter leak. This happens mainly with D.E. filters and a filter leak can cause your water to be very cloudy or partially cloudy.

Solution: Take the filter apart and inspect it and if there are broken grids simply replacing them will solve the problem.

#5 Cause: Adding Soda Ash or Baking Soda to the pool. When you add base to the pool it can become cloudy for a short period of time. After a few hours or by the next day it should clear up. A good way to avoid this is to add the base directly to the skimmer.

Solution: Manually vacuum up the dust on the pool bottom, pool will clear up very quickly,

#6 Cause:  High Alkalinity or High Calcium Hardness. Not very common but this could also cause your pool to be cloudy. But these need to be very high for this to happen.

Solution: Add Muriatic Acid to lower down the Alkalinity.

These are the basic causes for cloudy pool water and they are easily corrected. It could also be something unusual but these are the most common causes I run into on my pool route.