Understanding Pool Water Chemistry

Pool Chemistry Isn't as Complicated as it Sounds

Many pool owners think water chemistry is a complicated science. In reality, it comes down to keeping four important things in balance. When those four work together, your pool is easier to maintain, your water feels better to swim in and your equipment lasts longer.

Think of your pool like baking a cake. The ingredients all matter, but it's the balance between them that produces the best result.

1. pH – How Comfortable Your Water Feels

pH measures how acidic or alkaline your pool water is. Water with a balanced pH feels comfortable on your skin and eyes while helping chlorine work efficiently.

• Too low – water may become corrosive and irritate eyes and skin.
• Too high – water can become cloudy and chlorine becomes less effective.
• Ideal range: 7.2–7.6

2. Total Alkalinity – The pH Stabiliser

Total alkalinity acts like a shock absorber for your pool. It helps prevent your pH from constantly moving up and down.

• Low alkalinity often causes unstable pH.
• High alkalinity can make pH difficult to adjust.
• Ideal range: 80–120 ppm

3. Calcium Hardness – Protecting Your Pool

Calcium hardness measures the amount of dissolved calcium in the water.

• Too little calcium can encourage water to draw minerals from plaster, grout and some surfaces.
• Too much calcium may lead to scale forming on equipment and pool surfaces.
• Typical range: 200–400 ppm (depending on pool finish).

4. Chlorine – Keeping Water Safe

Chlorine sanitises your pool by destroying bacteria and other unwanted contaminants. Balanced water allows chlorine to work more effectively, meaning you often need fewer corrective chemical treatments.

• Ideal free chlorine: 1–3 ppm
• A strong chlorine smell usually indicates chloramines rather than too much chlorine.

How They Work Together

Good pool care isn't about chasing one number. When pH, alkalinity, calcium hardness and chlorine are all within their recommended ranges, your pool becomes easier to manage and far more enjoyable to swim in.

Water Balance	Recommended Range
pH	7.2 – 7.6
Total Alkalinity	80 – 120 ppm
Calcium Hardness	200 – 400 ppm*
Free Chlorine	1 – 3 ppm

*The ideal calcium hardness range varies depending on the type of pool surface and equipment.

Simple Weekly Routine

1. Test your water.
2. Adjust pH if required.
3. Check alkalinity.
4. Maintain the correct chlorine level.
5. Inspect the pool for clarity and cleanliness.

The Fresh Water Difference

At Fresh Water Pools Brisbane we believe understanding your pool should be simple. When your water is balanced correctly, you'll spend less time worrying about maintenance and more time enjoying crystal-clear water with family and friends.