Pool Troubleshooting /
How to Clean Algae From a Pool Safely and Effectively
To get rid of pool algae, remove debris, brush all affected surfaces, vacuum loosened material, clean the filter, and keep circulation running correctly.
Archive date: this article was written for PoolSkimmer on Oct 23, 2026 and given the earlier archive date of Sep 19, 2026 so the blog reads as an organized archive. It was not published on that date.
The first order of business in dealing with pool algae is to get in and do some physical work. Skim off the debris, give the walls and floor a good brushing, vacuum up what has been loosened and see to the skimmer and filter. Since algae tends to make itself at home where circulation is poor or water care has been neglected, a proper cleanup must address both the pool and its equipment.
How does algae get in a pool?
It is not hard for spores to find their way in via wind, rain, swimmers or even toys and other detritus around the pool. From there, they will put down roots if sanitation is lacking or the water is not being moved around enough. In most cases, you will find it simpler to head off an outbreak than to put in the work to remove one.
Some of the usual suspects for an algae problem are:
- Circulation that is either weak or too brief
- A clogged filter or an overfull skimmer basket
- Debris left on the bottom, walls or surface of the pool
- Pool chemistry that is out of whack, such as low free chlorine (depending on your system)
- Dirt and moisture held in by a cover or landscaping
What to do first to rid the pool of algae
Before any more forceful treatment, start with a thorough going-over:
1. Clear the surface of leaves, insects and anything else floating about. 2. Shut the pump down before you open the skimmer basket to clean it. 3. Put a brush to the floor, steps, ladders and fixtures to dislodge the algae. 4. Where your pool’s layout allows, work in a direction that lets the system capture the debris.
This is important. Brushing breaks the film and gets at the dead algae so it can be removed, while also taking away the organic material the algae feeds on.
Removing the dead algae
Once you have brushed, take your time and vacuum slowly; this way the loosened matter is collected rather than drifting back into the water. As Hayward would have it, you can vacuum the bottom for the brushed material after the fact. Be sure to consult your manual for how to set up and run the vacuum.
A sensible approach is to brush, then vacuum the settled debris, check the pump strainer and skimmer basket, and finally clean the filter in line with the manufacturer’s instructions. Whether you are running a sand or cartridge unit, the method is dictated by the equipment. There is no need to guess, just read the manual.
Why it seems to come back
When algae reappears, there is typically an underlying issue with the pool. You may notice the water going cloudy or green again in short order, or perhaps the filter pressure is not right. If you are still finding it in the corners and on the walls, or debris is piling up fast after you have brushed, the pool is calling for better circulation, more rigorous maintenance or a review of the water chemistry. Heed the chemical labels and never mix products unless the label says it is okay.
Preventative maintenance
Consistent care is the best defence against algae. Make a habit of skimming and brushing, and vacuum when necessary. Run the pump for the duration the manual recommends to ensure filtration is adequate, and test the water often to keep sanitizer levels in check. Keep the filter clean on schedule and try to limit the number of tree clippings and toys in the water.
Time to call in a professional
If you have put in the work and the algae is back, or if the water remains unsafe and cloudy, it is time to contact a qualified pool pro. The same goes if the pump or circulation system is not performing as it should, or if you have reason to think there is a fault with the plumbing, suction or electrics.
Never swim if the water is visibly compromised or if there is an electrical issue with the equipment. And for your own safety, turn the pump off before accessing the skimmer, put on the proper PPE and follow the manuals.
Sources and further reading
- [Hayward: Weekly pool maintenance](https://www.hayward.com/maintenance/weekly-pool-maintenance)