Expert Verified Updated: March 2026

Cal-Hypo Pool Shock Calculator

Quick, powerful, and effective. Calculate the exact number of bags needed to boost your chlorine levels and kill algae fast.

Quick Conclusion
To raise Free Chlorine (FC) by 10 ppm in a 10,000-gallon pool, use 1.1 lbs of 65% Cal-Hypo shock. One standard 1 lb bag of 65% shock provides a 5 ppm boost in 15,000 gallons.

Technical Comparison

Cal-Hypo Strength Amt for 1 ppm (10k Gal) CH Addition (per 10ppm FC)
65% (Standard) 2.1 oz ~7 ppm
73% (Pro-Grade) 1.8 oz ~6 ppm
43% (Value) 3.1 oz ~10 ppm

Actionable Steps

Pro-Tip

The Skimmer Rule: Never add Cal-Hypo shock to the skimmer if you have a chlorine feeder (puck feeder) attached. Mixing different types of chlorine in a confined space can cause a violent explosion.

Frequently Asked Questions

When to shock?

At night, to prevent sunlight from burning off the chlorine.

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