Pool Troubleshooting /
How to Remove Algae from Pool Walls
Brush algae loose, vacuum the debris, clean the skimmer and filter, and keep circulation strong. If green growth returns, check water balance and call a pro.
Archive date: this article was written for PoolSkimmer on Oct 23, 2026 and given the earlier archive date of Feb 3, 2026 so the blog reads as an organized archive. It was not published on that date.
Fastest and safest way to clear algae from pool walls
Start by brushing the walls to break up the algae, then put in some time with the vacuum and filtration to clear away what has come loose. The pump and filter should be on during this process; only shut the pump off when it is time to empty the skimmer basket. Should the water go green again, look beyond the walls for the cause – it could be a matter of sanitation or poor circulation.
Avoiding the spread of algae
The trick is not to scrub the algae back into the water but to get it into the circulation path. A pool brush is the tool for the job; work your way down from the top of the wall so any loosened material can be caught. Hayward’s own maintenance advice is to brush regularly and guide sediment to the main drain to make vacuuming easier.
Here is a sensible order of operations:
1. Shut down the pump before you open or empty the skimmer. 2. Give the walls a good brushing, particularly any that are stained, shaded or slippery. 3. Allow the dislodged algae to settle where the vacuum will find it. 4. Vacuum as per the instructions in your manual. 5. Tidy the skimmer and backwash or clean the filter if the equipment requires it.
When you are dealing with chemicals or a dirty basket, wear the proper PPE. Rely on the manufacturer’s label and manual, not what one might read online.
Dealing with persistent algae
If it keeps coming back, the water is likely not being sanitized or circulated to standard. Algae spores like to make themselves at home in poorly circulated spots such as behind fittings, in corners, or on the steps.
Some typical culprits are an infrequent brush routine, a clogged skimmer, a filter that is due for a cleaning, or a pump that is not running long enough. Then there is the water chemistry. Test often and adhere to the chemical label for treatment; do not make up your own mixing ratios. When in doubt as to whether it is a chlorine issue or something else, have a professional take a look.
Is the kind of algae important?
It is. You will most often see green algae which yields to a bit of brushing and good sanitation. Black algae is far more tenacious on the walls and mustard algae has a dusty appearance and a habit of returning. These are not always solved with routine care.
Call in a qualified pro if you notice dark spots that will not budge after you have brushed them, or if a storm or equipment glitch has left you with a heavy infestation and green water.
What to avoid
There are some habits that will only compound the problem:
- Brushing without following up to vacuum the debris
- Letting the skimmer basket fill with dirt
- Neglecting the filter
- Not giving the low-flow or shaded areas their due
- Putting a hand in operating suction gear
- Swimming in water that is clearly unsafe or where there is an electrical fault
Time to call for help?
If the pool remains cloudy or green despite your best efforts, or the filter system is not performing as it should, a technician can put an end to the guesswork and check your equipment. For the majority of homeowners, however, the answer is a straightforward regimen of brushing, vacuuming, keeping the water in motion and tending to the filter. It is the surest way to keep the algae at bay.
Sources and further reading
- [Hayward: Weekly pool maintenance](https://www.hayward.com/maintenance/weekly-pool-maintenance)