You should add calcium hardness to your pool water once the concentration falls below 150 ppm.
Maintaining the correct calcium hardness level is crucial for pool health and longevity. According to guidance, while the ideal range for calcium hardness is typically between 200 ppm and 400 ppm, you have some flexibility on the lower end. However, to proactively protect your pool surfaces and equipment, it's recommended to take action specifically when your pool's calcium concentration drops below 150 ppm.
Understanding Pool Calcium Hardness
Calcium hardness refers to the amount of dissolved calcium in your pool water. When levels are too low, the water can become corrosive and start to leech calcium from pool surfaces like plaster, tile grout, and coping. This can lead to etching, pitting, and damage over time. When levels are too high, it can cause scaling on surfaces and equipment.
The Trigger Point for Adjustment
Based on the provided information, the specific threshold that signals it's time to add calcium hardness is clear:
- Ideal Range: 200 ppm - 400 ppm
- Action Required: Below 150 ppm
This means you don't necessarily need to add calcium as soon as it dips below 200 ppm, but must adjust it once it reaches or falls below 150 ppm to ensure your pool remains balanced and protected.
To ensure your pool water chemistry stays balanced after adding chemicals, it's also important to maintain a thoroughly cleaned pool environment.
How to Check and Adjust Calcium Hardness
- Test Your Water: Use a reliable pool water test kit or strips to measure your current calcium hardness level. This should be done regularly as part of your overall pool maintenance routine.
- Calculate: If your test shows the level is below 150 ppm, you'll need to calculate the amount of calcium chloride (the common chemical used to increase calcium hardness) needed to raise the level into the desired range (aiming for at least 150 ppm, ideally towards the lower end of the 200-400 ppm range initially).
- Add Chemical: Follow the product instructions carefully. Typically, calcium chloride is added slowly to the pool water, often dissolved in a bucket of pool water first, and then dispersed around the perimeter (away from skimmers).
- Circulate and Retest: Allow the pool water to circulate for several hours (or as directed by the chemical manufacturer) and then retest the calcium hardness level to ensure you've reached the target range.
Maintaining proper water balance, including calcium hardness, is a key component of effective pool care. By adhering to the recommended trigger point of 150 ppm, you can prevent potential damage and keep your pool in excellent condition.
