One of the most frustrating problems for any pool owner is walking outside to find crystal-clear water has suddenly turned green. Whether it happens gradually or seemingly overnight, a green pool is a sign that something isn’t working properly.
The good news is that, in most cases, a green pool can be restored without draining the water. The key is identifying the cause quickly and treating the problem correctly.
At Illawarra Pool Cleaning, we provide professional green pool recovery services throughout Wollongong, Shellharbour, Kiama and the South Coast. We’ve restored everything from lightly cloudy pools to pools so green you couldn’t see the bottom.
This guide explains why pools turn green, how to recover them and how to stop it from happening again.
What Makes Pool Water Turn Green?
In almost every case, green pool water is caused by algae.
Algae are microscopic organisms that naturally exist in the environment. Their spores are carried by wind, rain, leaves, birds and even swimmers. When pool water loses its ability to sanitise properly, algae multiply rapidly and begin colouring the water.
The longer algae are left untreated, the more difficult the recovery process becomes.
Low Chlorine Levels
The most common cause of a green pool is insufficient chlorine.
Chlorine destroys bacteria, algae and other contaminants. If chlorine levels fall too low, algae can begin growing within a short period, particularly during warm weather.
Low chlorine can be caused by:
- Heavy pool use
- Hot weather
- High UV exposure
- Poor chemical balance
- A faulty chlorinator
- Rain diluting the pool water
Regular water testing helps identify chlorine problems before algae develops.
Heavy Rain and Storms
Throughout the Illawarra and South Coast, heavy rain is one of the biggest contributors to green pools.
Rainwater affects pool chemistry by:
- Diluting chlorine
- Changing pH
- Washing dirt and organic matter into the pool
- Introducing algae spores
- Increasing phosphate levels
After significant rainfall, it’s a good idea to test your water and inspect your equipment before algae has a chance to establish itself.
Pool Pump or Filtration Problems
Even with perfect water chemistry, poor circulation can lead to algae growth.
Your pool pump and filter work together to circulate chemicals throughout the pool and remove contaminants.
Common equipment issues include:
- Pump failure
- Blocked skimmer baskets
- Dirty filters
- Broken timers
- Air leaks
- Reduced water flow
If water isn’t circulating properly, chlorine cannot reach every part of the pool effectively.
Incorrect Water Balance
Many people focus only on chlorine, but chlorine performs best when the rest of the water chemistry is balanced.
Poor water balance can reduce chlorine’s effectiveness.
Important levels include:
pH
High pH significantly reduces chlorine’s sanitising ability.
Total Alkalinity
Unstable alkalinity causes pH to fluctuate, making water more difficult to maintain.
Stabiliser
Too little stabiliser allows sunlight to destroy chlorine quickly, while excessive stabiliser can reduce chlorine efficiency.
Professional testing ensures every part of your pool chemistry works together.
Faulty Salt Chlorinator
Saltwater pools are not immune to algae.
If your chlorinator isn’t producing enough chlorine, your pool can quickly turn green.
Signs your chlorinator may require attention include:
- Low chlorine readings
- Low Salt” warnings
- Fault codes
- Reduced chlorine production
- Worn salt cell
- Inconsistent operation
Regular servicing helps identify chlorinator issues before they affect water quality.
Hot Summer Weather
Warm temperatures create ideal conditions for algae.
During summer:
- Chlorine is consumed more quickly.
- Swimmer load increases.
- UV breaks down chlorine faster.
- Organic contamination increases.
This is why many pools require more frequent servicing during the warmer months.
Can a Green Pool Be Saved?
Yes—in most cases.
Many homeowners believe they must drain a green pool, but this is rarely necessary.
Professional green pool recovery usually involves:
- Complete water testing
- Algae treatment
- Correct chemical balancing
- Filter cleaning
- Continuous circulation
- Follow-up water testing
Most pools can be restored without wasting thousands of litres of water.
How Long Does Green Pool Recovery Take?
Recovery time depends on:
- The severity of algae
- Water chemistry
- Filter condition
- Pump performance
- Weather
- Pool size
A lightly affected pool may begin clearing within 24–48 hours, while a severely neglected pool may take several days of treatment and filtration before returning to crystal-clear condition.
How to Prevent Your Pool Turning Green
Prevention is always easier than recovery.
We recommend:
- Professional water testing every two to four weeks
- Keeping chlorine at the correct level
- Maintaining balanced pH
- Running the pump for the recommended hours each day
- Cleaning skimmer and pump baskets regularly
- Backwashing or cleaning filters when required
- Brushing walls and steps weekly
- Removing leaves and debris promptly
- Booking regular professional pool servicing
A preventative maintenance program is the easiest way to avoid algae outbreaks.
Green Pool Recovery Across the Illawarra
Illawarra Pool Cleaning provides professional green pool recovery throughout:
- Wollongong
- North Wollongong
- Fairy Meadow
- Corrimal
- Bulli
- Woonona
- Thirroul
- Shellharbour
- Shell Cove
- Albion Park
- Kiama
- Kiama Downs
- Minnamurra
- Jamberoo
- Gerringong
- Gerroa
- Berry
- Shoalhaven Heads
Whether your pool is slightly green or completely opaque, we have the experience and equipment to restore it quickly and safely.
Why Choose Illawarra Pool Cleaning?
Pool owners trust us because we provide:
- Fast response times
- Professional water testing
- Accurate chemical balancing
- Green pool recovery specialists
- Honest equipment advice
- Experienced technicians
- Quality pool chemicals
- Reliable workmanship
- Free quotations
Rather than simply treating the symptoms, we identify the underlying cause to help prevent the problem from returning.
Frequently Asked Questions
Is it safe to swim in a green pool?
No. Green water may contain algae, bacteria and poor water chemistry that can make swimming unsafe.
Can too much rain turn my pool green?
Yes. Heavy rainfall can dilute chlorine, upset water balance and introduce contaminants that encourage algae growth.
Will adding more chlorine fix a green pool?
Not always. If pH, filtration or circulation are incorrect, chlorine alone may not solve the problem. Professional testing is recommended.
Do I need to drain a green pool?
Usually not. Most green pools can be restored using professional chemical treatment, filtration and water balancing.
How can I stop my pool turning green again?
Regular servicing, balanced water chemistry, clean filters and correctly functioning equipment are the best ways to prevent algae.
Let Us Restore Your Pool to Crystal-Clear Water
A green pool doesn’t have to mean weeks of frustration or the expense of draining and refilling your pool. With the right treatment and professional advice, most pools can be restored quickly and safely.
At Illawarra Pool Cleaning, we specialise in diagnosing the cause of green pool water and delivering effective recovery solutions. Whether the problem is poor water balance, a faulty chlorinator, inadequate filtration or a combination of factors, we’ll get your pool back to healthy swimming condition.
Call 0410 981 271 today for a free quote on professional green pool recovery anywhere across Wollongong, Shellharbour, Kiama and the South Coast.