1. What is phenol red used for? Used to measure pH.
2. How do you know valves are open in a parallel system? The handle is parallel
to the pipe.
3. What does pH indicate in pool water? How acidic or basic a solution (pool
water) is.
4. What is the acceptable range of Total Alkalinity in a pool? 60 to 180.
5. What is the acceptable range of pH in a pool? 7.2 to 7.8.
6. What is the acceptable range of calcium hardness in a pool? 150 to 400.
7. What is the maximum reading for total dissolved solids (TDS)? 1500.
8. What is the pH of a human eye? 7.5.
9. What is the maximum time someone should spend in a spa? 15 minutes.
10. What is the maximum turnover rate for a main pool? 8 hours.
11. What is the maximum turnover rate for a wading pool? 2 hours.
12. What is the maximum turnover rate for a spa? 30 minutes.
13. What is the maximum temperature for a spa? 104 degrees.
14. What is the acceptable range for the Langelier Saturation Index? -0.5 to
+0.5.