Pool Troubleshooting /
How to Get Rid of Green Algae in a Pool
Green algae usually means circulation, filtration, or sanitizer levels have fallen behind. Brush, vacuum, clean the skimmer and filter, and follow the pool chemical label.
Archive date: this article was written for PoolSkimmer on Oct 23, 2026 and given the earlier archive date of Aug 29, 2026 so the blog reads as an organized archive. It was not published on that date.
First steps for a pool owner with green water
When you are faced with a swimming pool full of green algae, prompt action is in order. You want to restore circulation and get the algae off the walls, floor and corners before it has a chance to spread. The idea is to dislodge it so the filter can do its job. Be sure to consult your chemical labels and equipment manuals as you go about removing debris and brushing the pool.
A step by step approach to removing algae
There is a practical way to handle this:
1. Shut down the pump prior to any work on the skimmer basket. 2. Clear the surface of leaves and other floating matter. 3. Give the walls, ladders, steps and fixtures a good brushing to break up the algae. 4. Vacuum up what you have loosened from the bottom. 5. See to the skimmer and pump strainer baskets. 6. Check the filter and backwash or clean in line with the manufacturer’s instructions.
As Hayward puts it in their maintenance advice, running the pump is key to filtration and chemical efficacy, while brushing and vacuuming are what keep the algae in check.
The pool is still green. Why?
Sometimes after a cleaning the water remains cloudy or green because an element of maintenance has been overlooked. It could be that the sanitizer levels or pH are not where they should be, or there is weak circulation. Debris left on the pool floor for too long will do it, as will a clogged filter or skimmer. Even if you have brushed the algae, if it is still in the water the problem persists. An improperly set water level can also hamper the skimmer and allow algae to make a comeback.
Mistakes that complicate matters
Some errors will make for a more arduous cleanup. Do not brush without following up with a vacuum, or leave the pump off while debris is settling. Ignoring test results for chlorine and pH is another misstep, as is using chemicals without first reading the label. And under no circumstances should one put a hand into suction equipment that is running; if access to the skimmer is required, turn the pump off and refer to the manual.
Is it safe to swim?
In most cases the answer is no. If the water is green or cloudy, hold off on swimming until it is clear and safe. Should you notice anything amiss with the pump or suspect an electrical fault, have everyone stay out and contact a professional.
Time to call in an expert?
If regular maintenance does not stop the pool from turning green, or you are dealing with a damaged filter that clogs on a regular basis, it is time to get some help. A qualified pool pro is also the right call if you cannot safely diagnose a circulation issue or have pump troubles.
Keeping the algae at bay
Once the water is clear, a straightforward routine will suffice. Make a habit of skimming and vacuuming settled debris, and give the walls and fixtures a weekly brush. Keep the skimmer baskets and filter in good order and run the pump for adequate filtration. Test the water frequently and only adjust chemistry as the label instructs. For the safest handling of pool chemicals, wear the appropriate PPE and adhere to the manufacturer’s directions.
Sources and further reading
- [Hayward: Weekly pool maintenance](https://www.hayward.com/maintenance/weekly-pool-maintenance)