Cleaner. Clearer. Healthier.
Green Pool Water
A pool goes green because algae has outgrown the free chlorine holding it back. Usually that follows a hot spell, heavy rain, a filter that has not been backwashed, or a fortnight away with the cover on.
Clearing it is a sequence, not a single product. Test and correct pH first, because chlorine works poorly above 7.6 and you will burn through shock for nothing. Then shock the water hard, brush the walls and floor to break up anything clinging on, and run the filtration continuously until the water turns from green to cloudy grey. That colour change is the algae dying. Algaecide goes in afterwards to help control regrowth while your chlorine level rebuilds.
Expect two to three days for a badly affected pool, and expect to backwash or clean the filter more than once as it loads up with dead algae.
Everything below covers the chemical side of that sequence.
Eliminates Algae
Kills & prevents green algae
Restores Clarity
Crystal clear water
Protects Your Pool
Protects Your Pool
Trusted Quality
Professional grade products
Best Products to Fix Green Pool Water
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CrystaLux pH Plus Pool & Spa pH Increaser
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CrystaLux Pool Algaecide
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How to Clear Green Pool Water
Follow these steps in order to treat algae, restore water clarity and help your pool recover safely.
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Test the water
Check chlorine and pH levels before adding treatment.
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Adjust the pH
Bring the pH into the range recommended on your product label.
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Brush the pool
Brush the walls, floor, steps and corners to loosen algae.
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Apply shock chlorine
Dose according to the pool volume, test results and product label.
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Run the filtration system
Keep the water circulating and clean or backwash the filter as required.
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Retest before swimming
Wait until the water is clear and chemical levels are within the recommended range.
Always follow the instructions on each product label. Retest the water before swimming and wait until the water is clear and chemical levels are within the recommended range.
Treatment timeline
How long does green pool water take to clear?
Treatment time depends on the algae level, water balance, circulation, filtration and pool size.
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24 to 48 hours
Light green water
You can still see the pool floor. With the correct shock dose, a thorough brush and the filter running, the water usually starts clearing within a day or two.
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2 to 5 days
Dark green water
The floor is hidden and algae is well established. Expect a stronger dose, a repeat treatment after 24 hours if needed, and continuous filtration until the green fades.
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1 to 3 days extra
Cloudy after treatment
Cloudy water after shocking is a good sign. It means the algae is dead and waiting to be filtered out. A clarifier speeds this up, and backwashing keeps the filter working.
Stay clear all season
Keep it from turning green again
Clearing a green pool costs far more time and chemicals than preventing one. A simple weekly routine keeps the water clear all season.
- Test the water Check free chlorine and pH so problems are caught before the water changes colour. Weekly
- Top up sanitiser Keep free chlorine within the recommended range. Even a short drop can start an algae bloom. Weekly
- Dose maintenance algaecide A regular preventative dose stops algae taking hold between treatments. Weekly
- Run the filtration Moving water is harder for algae to colonise. Run the pump daily, longer in warm weather. Daily
- Brush and skim Brush walls, steps and corners and skim debris so algae has nowhere to settle. Weekly
CrystaLux
Pool & Hot Tubs
Keep your pool or hot tub clear and inviting by using the right chemicals regularly.
Need help?
Frequently Asked Questions
No. Wait until the water is clear and sanitiser and pH readings are within the safe range stated on the relevant product labels.
Usually not. Green water normally requires correct water balance, adequate chlorine, brushing and filtration.
Possible causes include incorrect pH, insufficient dosing, poor circulation, filter problems or metals in the water.
In most cases, circulation and filtration are essential. Follow the instructions for your equipment and chemicals.
Rain can dilute sanitiser levels and introduce debris, while warm conditions can encourage algae growth.
