Why Is My Pool Turning Green?

  • Apr 23, 2024
  • 755
Why Is My Pool Turning Green?

And how do I fix it? Keep reading for helpful hints on how to keep your pool sparkling and clear.


Pool water that’s turning green is often a sign that there’s something off-balance in the water. The good news is that there are a few tips and tricks you can implement into your pool-care routine to always keep your water looking fresh and clean!

Why is my pool turning green?

Green pools are caused by the build-up of bacteria and algae in the water, which can stem from:

1. Imbalanced Chemicals


The key to chemical balance is maintaining the proper pH levels (7.3-7.8) and free chlorine levels (1-3 ppm). If either of these levels are imbalanced, then there isn’t enough disinfectant in the water to keep bacteria and algae at bay. Use pool chemical test strips to easily check the chemical levels of your water.


2. Inclement Weather


A lot of rain and warm weather can actually cause extra bacteria growth in your pool. The excess amount of rainwater or sun exposure can cause the chlorine levels to drop below what you would normally keep them at, especially if you live in areas with exceptionally warm weather, such as Arizona or Florida.


3. Clogged Filtration System


Proper filtration is vital for clean, sparkling pool water. If your filter pump is clogged, the cartridge needs to be cleaned or replaced, or the pump isn’t running often enough, you will have a backlog of bacteria and algae living in your pool. 


4. Improper Cleaning/Maintenance


The chemicals and filter pump can do a lot, but they can’t do it all! Vacuuming and scrubbing the pool are also necessary to make sure it stays clean and clear all season long.

1. Check the Filter Pump


Unclog the filter pump and clean or replace the cartridge/backwash the sand so that you can start the filtration process from scratch.


2. Deep Clean with a Vacuum & Brush


Use a pool vacuum and brush to remove the debris from the bottom of the pool and dislodge the algae from the walls.


3. Test & Balance the Chemical Levels


Use test strips to check the free chlorine and pH levels, and adjust the chemical levels of the pool, if necessary.


4. Use a Shock Treatment


If the free chlorine level is too low to fix with chemical tablets, use a shock treatment to give the pool a high dose of chlorine designed to sanitize and deep clean the water.


5. Run the Filtration System for 24 Hours


Turn on your filter pump and let it run for 24 hours. This will give the water enough time to flow completely through the pump, removing any excess debris, bacteria or algae.


6. Check the Filter Pump (Again)


After a deep clean like the one you just completed, your filtration system is going to need a fresh start. Replace your filter cartridge or backwash your sand, then set the system to run as you normally would according to your manual.


7. Test & Balance the Chemical Levels (Again)


Use the test strips again to make sure the chemical levels are balanced and where they should be and adjust the levels if needed.

How do I prevent my pool water from turning green again?


Keeping up with pool maintenance is the most promising way to keep your pool water from turning green, and it can be done in 2 simple steps.


Test your pool water and adjust the chemical levels as needed. You may need to do this daily in times of heavy use or warm weather.


Maintain clean water by running the filter pump regularly and cleaning out the debris with a vacuum, brush or skimmer.


Don’t let green pool water dampen your summer family fun! Remember these helpful hints to enjoy clean and hygienic water all season long.


Read more of our pool tips and tricks in the Above Ground Pools section of the Bestway Beat.


Every article is researched and created by experienced copywriters, product and industry experts and outdoor enthusiasts who want to enrich your life with fun, adventure and happiness!

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