Learn how to test calcium hardness. Fill to 25 ml, add 20 drops of R10 and 5 of R11—sample turns red. Add R12 drop by drop until it turns blue. Multiply drops by 10 for ppm. Ideal range: 200–400 ppm (optimal: 300–325 ppm) to protect surfaces and grout.
Course Versions
- The Leading Edge of Maintenance | Pool Series - Calcium Hardness
- The Leading Edge of Maintenance | Pool Series - Calcium Hardness (Spanish)
Languages
- English
- Spanish