Water balance calculator

Calcium hardness

Account for calcium-chloride form and purity before planning an increase.

A pool water sample and testing kit beside clear blue pool and spa water

Measured inputs

Plan a staged increase

Use fresh test results and confirm every product value against its label.

Water volume (US gal)Volume unitsCurrent CH (ppm)Target (ppm)Product purity (%)Use the package label, not a generic product name.Calcium chloride formThe wrong molecular form materially changes the dose.

Staged treatment plan

8,341 g full amount

Start with 4,170 g (147.1 oz), circulate as labeled, then retest.

Product effectsRaises calcium hardness and adds chloride/TDS. Calcium chloride can release heat when dissolved; follow the product label exactly.

Formula: CaCO3-equivalent demand × calcium-chloride-form conversion ÷ purity
Assumptions: Calcium chloride dihydrate molecular-form conversion is applied. 50% staged-dose planning factor; confirm product form and purity on the label.
Source: Water-balance methodology · verified July 22, 2026

How to use this result

A planning quantity, not an instruction to pour.

1. Verify

Recheck volume, test reading, product strength, density or purity, and the selected target.

2. Read the label

Use the label’s application method, protective equipment, maximum dose, spacing, and re-entry directions.

3. Add separately

Never combine chemicals. Add one product at a time with circulation as directed.

4. Retest

Start with the staged amount, allow the label-directed circulation time, and measure again.