Pool Chemical Calculator — Canada
Metric by default: grams and kg alongside oz/lbs. ppm = mg/L.
Water Chemistry Guide
pH (7.2-7.6)
Affects chlorine effectiveness and swimmer comfort
Free Chlorine (1-3 mg/L)
Kills bacteria and algae to keep water sanitized
Total Alkalinity (80-120)
Stabilizes pH and prevents fluctuations
Calcium (200-400)
Prevents surface damage and cloudiness
Cyanuric Acid (30-50)
Protects chlorine from UV degradation
Safety First
- • Always add chemicals to water, never water to chemicals
- • Wear protective gloves and eyewear
- • Work in a well-ventilated area
- • Never mix different chemicals together
- • Store chemicals in a cool, dry place
Testing Tips
- • Test water 2-3 times per week during swim season
- • Test in the morning before the sun affects readings
- • Collect water sample 12-18 inches below surface
- • Wait 4-6 hours after adding chemicals before retesting
Pool chemical FAQs
In what order should I adjust pool chemicals?
Total alkalinity first (80–120 mg/L), then pH (7.2–7.6), then chlorine. Calcium and stabiliser last — each step moves the next, so opening with balanced alkalinity saves a season of chasing pH.
Why won't my chlorine hold?
Check stabiliser (CYA) first: over 100 mg/L it locks chlorine and only a partial drain fixes it. Otherwise suspect strong sun with no stabiliser, or combined chlorine needing a shock before closing season.
How often should I test pool water?
Two to three times a week in swim season, mornings before sun affects readings. Always wait 4–6 hours after adding chemicals before retesting.
Why does my pH keep drifting up?
Usually low alkalinity failing to buffer, aeration from features, or a salt system drifting high by nature. Fix total alkalinity into 80–120 first, then reset pH.
Is salt pool chemistry different?
Same targets, with pH drifting higher and salt to hold at 2700–3400 mg/L for Canadian cells. Size it with our salt water calculator.