Pool Stabiliser Calculator Australia
Work out how much cyanuric acid (CYA) to add to an outdoor chlorine pool. Dose from a reliable test, add in stages, and stop before stabiliser makes chlorine less effective.
What CYA level should you target?
- For outdoor chlorine pools, 30 ppm is a practical starting target; Queensland guidance says ideally 30 ppm or less and no more than 50 ppm.
- CYA protects free chlorine from Australian UV, but excess CYA slows disinfection and is normally reduced by dilution.
- Do not use CYA in indoor pools, spas, bromine pools, or Naked freshwater systems.
Australian dose chart
For near-pure stabiliser, grams required ≈ pool litres × desired ppm increase ÷ 1,000. Check product concentration and label directions before dosing.
| Pool volume | Raise CYA by 10 ppm | Raise CYA by 20 ppm |
|---|---|---|
| 30,000 L | 300 g | 600 g |
| 50,000 L | 500 g | 1.0 kg |
| 75,000 L | 750 g | 1.5 kg |
| 100,000 L | 1.0 kg | 2.0 kg |
How to dose without overshooting
- Test CYA with a suitable kit; do not calculate from how much product was previously added.
- Subtract the current reading from the target. If already near 50 ppm, do not add more.
- Calculate the dose, then follow the product label—many products are added through a skimmer sock or dissolved gradually.
- Run circulation and allow the product’s stated mixing time before retesting.
- Avoid topping up with stabilised chlorine once CYA is near its upper limit.
Want the numbers worked out for you? Enter your pool volume and test results in our pool chemical calculator to see every dose in one check.
Safety and system checks
- Never mix pool chemicals or add water to concentrated chemicals.
- CYA is lost mainly through water replacement, splash-out, or backwashing; high readings generally require partial drain and refill.
- Follow your sanitiser and pool-surface manufacturer when its target is narrower.