Calculate how much cal-hypo (65% / 68%) to add to raise Free Chlorine (FC).
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Enter total pool gallons.
Use what’s on your bag.
Enter your values and press Calculate. Inputs are saved on this device.
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Important: Cal-hypo adds calcium hardness (CH) over time. If your CH is already high, liquid chlorine is usually the safer long-term choice.
Never mix cal-hypo with trichlor/dichlor products.
How to Use This Cal-Hypo Calculator
Enter pool gallons, current FC, target FC, and cal-hypo strength.
The calculator estimates how many ounces and pounds of granular cal-hypo to add.