When your pool water starts looking cloudy, feeling harsh on the skin, or taking on a greenish hue, the problem almost always comes back to one thing: water chemistry.
For pool owners in Perth, where weather and usage can fluctuate dramatically, understanding your pool’s chemical balance is essential. Not only does it keep your water clean and safe, but it also protects your pool’s surfaces, equipment, and overall performance.
Let’s take a closer look at what pool chemistry actually means, why it matters, and how you can manage it with confidence.
Key Takeaways
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Balanced pool chemistry is essential for clear, safe water and protecting your pool equipment.
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The five core elements to monitor are pH, total alkalinity, chlorine, calcium hardness, and stabiliser.
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These elements work together; if one is off, it can affect the performance of the others.
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Environmental factors like rain, heat, and swimmer load can throw your water out of balance quickly.
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Regular testing is key. DIY weekly checks and monthly professional testing help catch issues early.
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Simple routines prevent big problems. Staying consistent saves time, money, and hassle in the long run.
Why Pool Chemistry Isn’t Just About Chlorine
Chlorine is often the focus, but pool chemistry goes well beyond sanitising. It’s about maintaining the right chemical balance to keep your water safe, clear, and comfortable.
When everything is in balance:
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Chlorine works efficiently to kill bacteria and algae
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The water looks clean and feels comfortable
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Surfaces and internal systems are protected from corrosion or scale
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Pool ownership becomes far less stressful
And when the chemistry is off? You’re looking at problems like algae growth, cloudy water, irritated skin, and long-term pool equipment damage.
The Five Essentials of Pool Chemistry
To keep your pool water healthy, clear, and safe to swim in, there are five core chemical levels you need to keep an eye on and maintain.
1. pH: The Foundation of Balance
pH measures how acidic or alkaline your water is. It directly affects swimmer comfort, the effectiveness of chlorine, and the longevity of your pool equipment.
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Ideal range: 7.2 to 7.6
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Low pH can cause corrosion and skin or eye irritation
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High pH reduces chlorine efficiency and leads to scale formation
Even small shifts in pH can throw off your water chemistry, so it’s important to test it regularly.
2. Total Alkalinity: The pH Stabiliser
Alkalinity acts as a buffer, helping to stabilise pH and prevent sudden changes.
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Ideal range: 80 to 120 ppm (parts per million)
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Low alkalinity causes pH to fluctuate
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High alkalinity makes pH harder to adjust and can lead to cloudy water
If your pH keeps fluctuating, start by checking your alkalinity.
3. Chlorine: The Primary Sanitiser
Chlorine disinfects your pool by eliminating bacteria and algae. It’s one of the most important elements in maintaining safe water.
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Ideal range: 1.5 to 3.0 ppm
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Too little: algae and bacteria can take over
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Too much: may irritate eyes and skin
For chlorine to work effectively, your pH and stabiliser levels must be in range. All these elements are closely connected.
4. Calcium Hardness: Surface and Equipment Protection
Calcium hardness refers to how much dissolved calcium is in your water. It helps prevent corrosion and scale.
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Ideal range:
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200–225 ppm for concrete or tiled pools
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175–225 ppm for fibreglass or vinyl
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Low calcium: causes water to draw minerals from pool surfaces
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High calcium: leads to scaling on tiles, heaters, and inside pipes
5. Stabiliser (Cyanuric Acid): Chlorine’s UV Shield
A stabiliser protects chlorine from being broken down by sunlight, which is especially important during long Perth summers.
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Ideal range: 35 to 50 ppm
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Too little: chlorine disappears quickly
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Too much: chlorine becomes less effective
Only use a stabiliser in outdoor pools. Indoor pools and spas don’t need it.
How the Chemistry Shifts Over Time
One of the challenges of maintaining pool chemistry is that it doesn’t stay still. Levels can be affected by:
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Rain, wind, and sunlight
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Swimmers, sunscreen, and body oils
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Leaf litter and garden debris
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Water top-ups or evaporation
Even if your pool looks clear, things can be off behind the scenes. That’s why regular testing is essential; prevention is always easier (and cheaper) than correction.
Signs Your Water Chemistry Needs Attention
Your pool will often give you subtle clues when something is wrong. Here’s what to watch for:
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Cloudy water: Often caused by high pH or low chlorine
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Green tinge or visible algae: A sign that chlorine levels have dropped too low
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Scale or white marks: Usually due to high calcium or pH
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Irritated skin and eyes: Can result from low pH or imbalanced chlorine levels
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Chlorine smell: Often indicates chloramines, not too much chlorine, usually a sign that chlorine isn’t working effectively
If you notice any of these signs, it’s time to test and adjust your levels.
Testing and Treating Pool Water: A Practical Approach
You don’t need to be a chemist to keep your pool water balanced, but a consistent a regular maintenance routine goes a long way.
Weekly (DIY)
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Test chlorine, pH, and alkalinity using test strips or a reliable kit
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Run your filter system for 8 to 12 hours a day (especially in summer)
Monthly (Professional Support Recommended)
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Test calcium hardness, stabiliser, salt levels (if applicable), and total dissolved solids
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Bring a water sample to Pool Assist or book a technician to visit
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Review equipment performance to ensure everything is circulating as it should
If anything’s out of balance, make small adjustments and retest within 24 hours. Avoid correcting everything at once; it’s more effective (and safer) to make changes gradually.
Take Control of Your Pool Water with Confidence
Keeping your pool water balanced doesn’t need to be complicated. With a bit of knowledge and regular care, it becomes a simple part of your routine, and the results are worth it. Clearer water, longer-lasting equipment, and safer swimming for everyone.
And if you ever want a hand with testing, balancing, or keeping things on track, Pool Assist is always here to help. From expert advice to professional servicing across Perth, we’ll make sure your pool stays in top condition, so you can focus on enjoying it.
Frequently Asked Questions
Q. What is the easiest way to maintain pool chemistry year-round?
A. The easiest method is to establish a weekly testing routine and invest in an automatic dosing system or professional pool servicing. This ensures consistent chemical levels without the guesswork, especially during seasonal changes.
Q. What causes chlorine levels to drop quickly?
A. High swimmer load, hot weather, heavy rainfall, and low stabiliser levels can all cause chlorine to deplete faster than normal. UV exposure from sunlight is a major factor in chlorine loss during summer.
Q. Does water temperature affect pool chemistry?
A. Yes, warmer water speeds up chemical reactions and can reduce chlorine effectiveness. High temperatures also encourage algae growth, making chemical balance more important during summer.
Q. How often should I test my pool water?
A. Basic chemical levels like pH and chlorine should be tested at least once per week. Monthly testing by a pool professional is recommended for more detailed levels, such as calcium hardness and stabiliser.
Q. Can pool chemistry impact how long my pool equipment lasts?
A. Absolutely. Water that’s too acidic or too hard can corrode pipes, damage filters, and shorten the life of pumps and heating systems. Proper chemistry maintenance helps extend equipment lifespan and avoid unnecessary repairs.