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Pool Shock Calculator/Green Pool Shock Calculator
Target Free Chlorine: +30 PPM

Green Pool Shock Calculator

Triple-Dose Superchlorination Guide to Eradicate Green Algae

Clearing a green pool requires hitting Breakpoint Chlorination (30 PPM Free Chlorine). A mild routine shock of 10 ppm will not kill active algae; it will merely feed it. Calculate your emergency mega-shock dose below.

Customize Your Pool Parameters

Adjust pool volume or shock severity to re-calculate instantly.

Most Popular
Calcium Hypochlorite (73%)
6 lbs
6 one-pound bags

Granular shock. Fast-dissolving, adds zero CYA stabilizer.

Cleanest / Zero Dust
Liquid Chlorine (12.5%)
4.8 gal
614 fluid ounces

Leaves zero residue, zero calcium, and zero CYA. 100% dissolved instantly.

Stabilized Shock
Sodium Dichlor (56%)
6.9 lbs
Adds approx 27 ppm CYA

Includes UV stabilizer. Ideal if your pool has low CYA (<30 ppm).

Recommended Commercial-Grade Pool Shock & Brushes

Avoid cheap big-box shock with low available chlorine (40–50%). Use 68–73% commercial Calcium Hypochlorite or 12.5% Sodium Hypochlorite for maximum algae kill rate.

The 3-Step Green Pool Eradication Process

1. Lower pH to 7.2: Chlorine is 60% more effective at pH 7.2 than at pH 7.8.

2. Scrub All Biofilms: Use a stiff brush to scrape algae off walls so chlorine can reach the root.

3. Triple Shock at Dusk: Add 3 lbs of Cal-Hypo per 10,000 gallons after sunset.

Why You Must Never Use Algaecide While Shocking

High chlorine levels break down quaternary and metallic algaecides, consuming your shock and precipitating copper stains. Only use superchlorination to kill green blooms; add preventative algaecide only after chlorine normalizes.

Related Pool Shock & Chemical Calculators

Frequently Asked Questions: Green Pool Shock Calculator

No. The sun's UV rays will destroy up to 50% of your shock within 2 hours. Always shock at or after dusk.
Within 12 to 24 hours of successful breakpoint shock, bright green water should turn a cloudy, milky white or grey, indicating all algae cells are dead.