1. What is Calcium Hardness?

Calcium hardness refers to the amount of dissolved calcium in your pool water. Proper calcium hardness levels (typically 200-400 ppm) help prevent plaster damage and water balance issues.

2. How Does the Calculator Work?

The calculator uses the calcium hardness adjustment formula:

Where:

• \( CH_{dose} \) — Pounds of calcium chloride needed
• \( V \) — Pool volume in gallons
• \( CH_{target} \) — Target calcium hardness (ppm)
• \( CH_{current} \) — Current calcium hardness (ppm)

Explanation: The formula calculates how much calcium chloride is needed to raise the calcium hardness from current to target level based on pool volume.

3. Importance of Calcium Hardness

Details: Proper calcium hardness prevents plaster etching (too low) or scale formation (too high). Ideal range is 200-400 ppm for plaster pools and 175-225 ppm for vinyl pools.

4. Using the Calculator

Tips: Enter pool volume in gallons, current and target calcium hardness in ppm. Target is typically 300 ppm for most pools. The result shows pounds of calcium chloride needed.

5. Frequently Asked Questions (FAQ)

Q1: What happens if calcium hardness is too low?
A: Low calcium can cause plaster etching, grout damage, and corrosion of metal fixtures.

Q2: What if calcium hardness is too high?
A: High calcium leads to scale formation, cloudy water, and reduced heater efficiency.

Q3: How often should I test calcium hardness?
A: Test monthly, or after adding large amounts of water to the pool.

Q4: Can I use calcium chloride flakes?
A: Yes, but account for purity (typically 94-100% for pool-grade calcium chloride).

Q5: How do I add calcium chloride to my pool?
A: Pre-dissolve in a bucket of water and distribute around the pool perimeter with pump running.