Sometimes, a pool can still look green even when there is enough chlorine. This can be confusing, but there are reasons why it happens. Let’s find out why and how to fix it!
Why Does Pool Water Turn Green?
- Stubborn Algae – Some types of algae, like mustard algae, don’t go away with chlorine alone. They keep growing and turn the water green.
- Wrong Water Balance – Chlorine works best when the pH level is just right. If the pH is too high or too low, chlorine won’t clean the water properly.
- Too Much Pool Stabilizer – Some pool chemicals contain cyanuric acid, which helps chlorine last longer. But too much of it can make chlorine weaker, letting algae grow.
- Dirty Filter – If the pool filter isn’t working well, dirt and algae stay in the water, making it look green.
How to Fix a Green Pool
- Check the Water – Use a test kit to check the chlorine and pH levels. Adjust them if needed.
- Run the Filter More – Keep the filter running all day to clean the water faster.
- Use an Algae Killer – If chlorine isn’t enough, add an algaecide to kill stubborn algae.
- Scrub the Pool – Brush the walls and floor to remove algae stuck to surfaces. Then, clean the filter.
- Change Some Water – If cyanuric acid is too high, remove some pool water and add fresh water.
Keep Your Pool Clean
If your pool is green, don’t just add more chlorine! Test the water, clean the filter, and adjust the chemicals. Regular care will keep your pool blue and safe for swimming!
Co-authored by:
James Hawkes
Swimming Pool Expert