Cloudy Pool Water: Causes & Cures
This video explains the most common causes of cloudy pool water and how to address them. Typically, there are only a few reasons why pool water becomes cloudy. Once the issue is resolved, the water should clear up within a few days.
I’m often asked whether a clarifier is necessary. In most cases, it’s not. I use clarifiers sparingly, usually when a customer is hosting a party or when I need to clear up a pool quickly for an event. While pool stores often promote clarifiers, they can be useful in certain situations. For example, if you have a sand filter, a clarifier can help by clumping particles together, making them easier to filter out.
Common Causes of Cloudy Pool Water and How to Fix Them
Cause #1: No Chlorine in the Pool
One of the most common reasons for cloudy water is a lack of chlorine. This can happen if you forget to check the pool, experience unusually hot weather, heavy rain, or host a pool party—all of which can deplete chlorine levels.
Solution:
Raise the chlorine level to 10 ppm to "shock" the pool and clear the water. Additionally, run your pool filter for an extended period to speed up the process.
____________________________
Cause #2: Combined Chlorine
If you've ever smelled a strong chemical odor at a pool (like at a hotel or gym), it’s not chlorine—it’s combined chlorine (chloramines). These form when chlorine reacts with contaminants in the water, creating an ammonia-like smell and cloudy water.
Solution:
Raise the chlorine level to 10 ppm to eliminate chloramines and restore clarity.
____________________________
Cause #3: Insufficient Filtration
Your pool needs at least one complete water cycle daily, meaning all the water passes through the filter and returns to the pool. If your chlorine levels are adequate but the water is still cloudy, your pool might not be running long enough.
Solution:
Ensure the pool runs long enough to complete at least one full cycle each day.
____________________________
Cause #4: Filter Leaks
Leaks in the filter, especially in D.E. filters, can cause cloudy or partially cloudy water.
Solution:
Disassemble the filter and inspect it for damage. Replace broken grids or other faulty components as needed.
___________________________
Cause #5: Adding Soda Ash or Baking Soda
Adding a base (like soda ash or baking soda) to the pool can temporarily cloud the water. However, this usually resolves itself within a few hours or by the next day.
Solution:
To minimize cloudiness, add the base directly to the skimmer.
___________________________
Cause #6: High Alkalinity or Calcium Hardness
While less common, very high levels of alkalinity or calcium hardness can also lead to cloudy water.
Solution:
Test and balance the pool's alkalinity and calcium hardness levels.
___________________________
Summary
These are the most common causes of cloudy pool water, and most issues are easily fixed with proper care and maintenance.
