Green Pool After Fall Rain? How to Clear It Fast in Georgia
Why your pool turns green after a storm and the exact steps to get it clear again.
A pool usually turns green after rain because the water dilutes your chlorine while washing in debris, leaves and phosphates that algae feed on. To clear it: test your water, clean your filter, balance your pH, brush everything, shock the pool, then run the pump continuously and keep brushing and cleaning the filter until the water is clear. Most green pools clear in a few days with the right steps.
Why rain turns pools green
Heavy rain does three things at once. It dilutes your chlorine, so there is less sanitizer working in the water. It can shift your pH, which makes the chlorine you do have less effective. And it washes in leaves, dirt and pollen that bring nutrients for algae. Add a few warm fall days and algae can take hold within days.
How to clear a green pool, step by step
- 1Test your water first. Knowing your chlorine, pH and stabilizer levels tells you how much work you have ahead and stops you wasting chemicals.
- 2Remove leaves and debris. Skim the surface, empty skimmer and pump baskets, and get as much off the floor as you can.
- 3Clean your filter. A dirty filter cannot trap dead algae, so start with it clean.
- 4Balance your pH. Chlorine works best when pH is in range, so adjust it before you shock.
- 5Brush the walls, floor and steps thoroughly. This breaks up algae so the chlorine can reach it.
- 6Shock the pool. Use a strong dose of shock, ideally in the evening so the sun does not burn off the chlorine before it works.
- 7Run your pump continuously. Keep the water moving and filtering around the clock until the water clears.
- 8Brush daily, clean the filter often and retest. Dead algae turns cloudy gray or white and settles. Vacuum it out, keep cleaning the filter and repeat the shock if chlorine drops before the water is clear.
Not sure how much to add? Bring a water sample to our Alpharetta store at 2900 Holcomb Bridge Rd for a free computerized water test. We will tell you exactly what your pool needs to clear up, and nothing it does not.
Know your algae
| Type | What it looks like | Good to know |
|---|---|---|
| Green algae | Green water or slimy green patches on walls | The most common type and usually the easiest to clear |
| Yellow or mustard algae | Yellow-brown powdery patches, often in shady spots | Brushes off easily but comes back if not fully treated |
| Black algae | Dark spots with roots that dig into plaster | The toughest type and needs aggressive brushing and treatment |
Mistakes that slow things down
- •Shocking without testing or balancing pH first.
- •Turning the pump off overnight before the water is clear.
- •Forgetting to clean the filter as dead algae builds up in it.
- •Not brushing, which leaves algae protected on the walls.
- •Swimming too soon. Wait until the water is clear and chlorine is back in a normal range.
Never mix pool chemicals together, and always add them to water following the label directions.
How to stop it happening again
Test your water after every heavy rain, keep leaves out during fall and keep your chlorine and pH in range. In leaf season, emptying baskets more often makes a big difference. Read our guide to keeping fall leaves out of your pool.
Frequently asked questions
Need help clearing your pool?
Bring a water sample to Pool Supply Atlanta, 2900 Holcomb Bridge Rd, Alpharetta, GA 30022 for a free computerized test. Open Monday to Friday 9am to 5pm and Saturday 9am to 4pm. Serving Alpharetta, Roswell, Milton, Johns Creek and Sandy Springs. Questions? Call 678-691-6124.
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