How to Balance Your Pool Water (pH, Alkalinity & Chlorine)
, by Splash Water Specialists, 3 min reading time
Learn how to balance your pool water like a pro — covering pH, total alkalinity, and chlorine levels. Step-by-step guide with NZ product recommendations.
Keeping your pool water balanced is the single most important thing you can do to protect your pool, your equipment, and the people swimming in it. Unbalanced water can cause skin and eye irritation, corrode your pool surfaces, and make your sanitiser far less effective. The good news? Once you understand the three key parameters — pH, alkalinity, and chlorine — it's straightforward to keep everything in check.
Step 1: Test Your Water First
Before adding any chemicals, always test your water. You can use test strips or a liquid test kit. For the most accurate results, bring a water sample into our store — we offer water testing and will give you a personalised treatment plan. A test will cost $6.00 or free if you spend $30.00 in store on the day.
👉 Shop Pool Water Testing Kits
Step 2: Adjust Total Alkalinity (Target: 80–120 ppm)
Total alkalinity (TA) acts as a buffer for your pH, preventing it from swinging wildly. Always adjust alkalinity before pH.
- Too low? Add an alkalinity increaser such as Balance Pak100, PH Buffer and sodium bicarbonate.
- Too high? Add pH reducer Lo N Slo or Hydrochloric Acid slowly, with the pump running.
👉 Balance Pak 100 – Alkalinity Increase
Step 3: Balance Your pH (Target: 7.2–7.6)
pH is the measure of how acidic or basic your water is. The ideal range is 7.2–7.6. Outside this range, chlorine becomes much less effective and swimmers may experience irritation.
- pH too high (above 7.6)? Add a pH decreaser or Lo N Slo.
- pH too low (below 7.2)? Add a pH increaser, Balance Pak 200 (sodium carbonate).
Step 4: Sanitise with Chlorine (Target: 1–3 ppm)
Chlorine is your pool's primary sanitiser, killing bacteria and algae. The ideal free chlorine level is 1–3 ppm for most residential pools.
- Granular chlorine (dichlor): Fast-dissolving, great for regular dosing.
- Slow-release tabs: Convenient for maintaining a steady level between treatments.
- Liquid chlorine: Fast-acting, ideal for shocking a pool.
👉 Swim Clear Granulated Pool Chlorine (Dichlor)
👉 Pacific Blue Power Tabs – Slow Release Chlorine
👉 Liquid Pool Chlorine (Click & Collect)
Step 5: Check Stabiliser (Cyanuric Acid) — Outdoor Pools Only
If you have an outdoor pool, cyanuric acid (CYA) protects chlorine from being broken down by UV sunlight. The ideal range is 30–50 ppm. Too high and it reduces chlorine effectiveness; too low and your chlorine burns off quickly. We have Stabiliser Powder, Liquid and Tabs.
How Often Should You Test?
During summer (swimming season), test your water at least 2–3 times per month. In winter, once a month is usually sufficient. After heavy rain or a big pool party, always test and re-balance before the next swim.
Need Help?
Not sure where to start? Bring a water sample into Splash Water Specialists — we'll test it for free and recommend exactly what your pool needs.
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