Whether you're dealing with cloudy water or a full-blown algae bloom, understanding what causes a pool to turn green is the first step toward fixing it. From faulty pool cleaning systems to lapses in regular care, this guide will walk you through why your pool turns green and what you can do about it.
Why Is My Pool Water Green?
Green pool water is almost always a sign of algae overgrowth, typically caused by one or more of the following:
1. Low Chlorine Levels
Chlorine is your pool’s frontline defense against bacteria and algae. If chlorine levels fall below the recommended range (2–4 ppm), even for a short time, algae can begin to form rapidly.
2. Poor Water Circulation
Pools that aren't circulating water properly allow spores and contaminants to settle. This is a common issue in shaded or older pools in Toorak, especially those without modern swimming pool cleaning systems Toorak homes are now adopting.
3. Warm Temperatures
Algae love heat. During Toorak’s warmer months, pools that aren't closely monitored can become algae breeding grounds in just a few days.
4. Excess Debris
Leaves, pollen, dirt, and other organic matter feed algae growth. Toorak’s lush gardens and tree-lined streets often contribute to these challenges.
5. Unbalanced pH or Stabiliser Levels
If your pH or stabiliser (CYA) levels are off, chlorine becomes less effective—giving algae the upper hand.
Signs That Your Pool Is Turning Green
Green water isn’t always the first warning sign. Watch for these early indicators that your pool needs attention:
A faint green tint or cloudiness
Slippery pool walls or steps
Visible algae spots in corners or on the floor
A strong chemical smell (ironically a sign of poor balance)
Reduced water flow from return jets
If you notice any of these, it's time to take action—whether you're handling it yourself or calling a Toorak pool cleaning service.
The Three Types of Pool Algae
Understanding what type of algae you're dealing with can help determine the right solution:
✅ Green Algae
Most common
Free-floating, causes cloudy or green water
Easy to treat with chlorine and brushing
✅ Yellow Algae (Mustard Algae)
Appears as dusty yellow patches in shady areas
More chlorine-resistant
Requires shock and thorough brushing
✅ Black Algae
Rooted in surfaces like tile grout or concrete
Extremely stubborn
Often needs professional removal by a pool cleaning service Toorak residents trust
How to Treat a Green Pool (Step-by-Step)
If you’re managing your own pool cleaning in Toorak, here’s how to reclaim your water:
1. Test and Balance the Water
Use a reliable test kit to check chlorine, pH, and stabiliser levels. Adjust as needed:
pH: 7.2–7.6
Chlorine: Raise to 10+ ppm to start
CYA: 30–50 ppm
2. Brush and Skim
Scrub all surfaces—steps, walls, and corners. Skim debris from the surface daily.
3. Shock the Pool
Use calcium hypochlorite shock (dosage depends on algae type). Shock in the evening and run the pump continuously for 24–48 hours.
4. Vacuum to Waste
Vacuum out dead algae directly to waste to avoid clogging the filter.
5. Clean the Filter
Backwash sand and DE filters, or rinse cartridge filters thoroughly.
6. Add Algaecide and Phosphate Remover
After chlorine levels return to normal, treat with a non-foaming algaecide and remove excess phosphates to prevent recurrence.
How to Prevent Green Pool Water Long-Term
Whether you're maintaining your own pool or rely on Toorak pool cleaning services, prevention is the best cure:
Keep chlorine between 2–4 ppm
Run the pump 8–12 hours a day
Test water weekly
Brush and vacuum weekly
Use algaecide during warmer months
Upgrade to modern pool cleaning systems Toorak experts recommend
Cover the pool when not in use
When to Call a Professional Pool Cleaning Service
If your pool stays green after treatment—or worse, turns black—it’s time to call a Toorak pool cleaning service. Professionals can:
Perform acid washes
Diagnose and fix circulation issues
Use commercial-grade algaecides and clarifiers
Offer automated maintenance solutions
Final Thoughts
So, what causes a pool to turn green? It’s usually a mix of low chlorine, poor circulation, and organic buildup—made worse by warm, sunny conditions.
Whether you're tackling this yourself or hiring a pool cleaning service Toorak residents rely on, staying ahead of algae is key. Regular testing, modern cleaning systems, and professional care can help you enjoy crystal-clear water all year long.
If you're based in Toorak, upgrading your equipment or routine might be all it takes to say goodbye to green water for good.
