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Pool Shock Calculator

Calculate the exact amount of shock to superchlorinate your pool for maintenance, chloramine removal, or algae treatment.

Shock Calculator

Superchlorinate to oxidize contaminants and kill algae

High Chloramines

Combined Chlorine (Chloramines)

1.0 ppm

High chloramines cause "chlorine smell" and eye irritation. Breakpoint chlorination recommended.

Pool Volume

20,000 gallons

Regular weekly shock to oxidize contaminants
Total chlorine should be close to free chlorine

Shock Amount Needed

1.6 lbs

Cal-Hypo Shock (65%)

Run pump for at least 8 hours after shocking

Tips

Routine maintenance shock

1 lb per 10,000 gal raises chlorine ~10 ppm

Add shock in evening for best results

Swimming Safety
Do not swim until chlorine level drops below 5 ppm. Test before allowing swimmers back in the pool. Shock treatment at dusk is most effective.

About Pool Shocking

Shocking (superchlorination) raises chlorine levels high enough to destroy organic contaminants, chloramines, and algae. It's an essential part of pool maintenance.

When to Shock

Weekly maintenance: Prevents buildup of contaminants.
Chloramine smell: That "chlorine smell" is actually chloramines - shock to eliminate them.
After heavy use: Pool parties, lots of swimmers.
Algae outbreak: Heavy shock to kill algae.
After rain: Storms can introduce contaminants.

Best Practices

Shock at dusk or night - sunlight destroys chlorine. Run the pump for 8+ hours. Don't swim until chlorine drops below 5 ppm. Pre-dissolve granular shock in a bucket before adding.