How to Shock a Pool ProperlyUpdated a month ago
Shocking your pool is essential for killing algae, bacteria, and contaminants—especially after heatwaves, heavy rain, or pool parties. Here’s how to do it right for crystal-clear water in Australia’s harsh conditions.
1. Test & Balance Water First
Check using a pool chemical test strip:
Free Chlorine: Ideal range 1–3 ppm.
pH: 7.2–7.6 (adjust with pH decreaser if too high).
Cyanuric Acid (CYA): 30–50 ppm (protects chlorine from UV).
Why it matters: High pH or low CYA reduces chlorine’s effectiveness.
2. Choose the Right Shock
| Type | Best For | Wait Time |
|---|---|---|
| Calcium Hypochlorite | Concrete pools, heavy contamination | 8–24 hours |
| Liquid Chlorine | Quick fixes, all pool types | 4–8 hours |
| Non-Chlorine Shock | Mild issues, swim-ready ASAP | 15–30 minutes |
Note: For saltwater pools, use chlorine-compatible shock (avoid calcium if hardness is high).
3. Calculate the Dose
Standard shock dose: 1 kg per 40,000L (adjust based on contamination level).
Heavy algae/contamination: Double the dose (e.g., 2 kg per 40,000L).
Formula:
4. Apply Shock Correctly
Time it right: Shock at dusk/night to prevent UV degradation.
Pre-dissolve granular shock: Mix in a bucket of water first (prevents bleaching surfaces).
Pour slowly: Distribute evenly around the pool’s perimeter.
Brush walls/floors: Helps shock reach algae and biofilm.
5. Circulate & Retest
Run the pump for 6–8 hours (overnight ideal).
Retest after 24 hours:
Chlorine should drop to 1–3 ppm.
pH may rise—rebalance if needed.
Vacuum debris: Dead algae or particles may settle.
Aussie-Specific Tips
Post-bushfire: Shock after ash falls to neutralise contaminants.
Heatwaves: Shock weekly in summer (high temps breed bacteria faster).
Heavy rain: Shock to combat diluted chemicals and runoff.
Saltwater pools: Check salt levels (Depending on you pool chlorinator) after shocking.
Safety Gear & Storage
Wear: Gloves, goggles, and old clothes (chlorine is corrosive).
Store shock: In a cool, dry place (away from kids/pets).
Dispose of packaging: Securely—windy days can scatter residue.
Need Shock or Test Kits?
Browse our Pool Shock Treatments and Test Kits for reliable Aussie brands. Pair with a robotic cleaner to tackle post-shock debris!
Final Tip: Shocking isn’t optional—it’s pool first aid! Stay ahead of green water and murky meltdowns with regular treatments.