Case Study: High pH Levels and Calcium are causing issues in my pool

Example Gunite Pool

Tom recently Asked the Pool Guy this question:

The pH keeps rising and the calcium level keeps rising in my pool. Is this normal? What can I do about it?

Here are the chemical levels and pool specs that Tom shared:

total chlorine (not tested)

free chlorine 1.0

PH 7.4

total alkalinity 110ppm

calcium hardness 480ppm

Salt Water Pool: 11,625 gallons, exposed aggregate, all the equipment is Jandy including the salt system

Shocking once a month (based on the pool store recommendation) and using calhypo shock

Ask the Pool Guy’s Advice on high pH levels and high Calcium in the pool

With a salt system we recommend keeping total alkalinity at 80 which helps keep the pH at a lower range. The process of producing chlorine in the pool constantly increases the pH levels – and we find when the alkalinity is kept at 80-100 it becomes more manageable. You will still need to monitor the pH and bring it down when it gets high.

You are right, calhypo shock would be contributing to your calcium issue. Switch to a sodium based shock product so you don’t add additional calcium into the pool. Also check your salt system to see if it has a “superchlorinate” mode. Usually that will shock the pool for 24 hours, and then go back into regular programming mode.

To get the calcium out of the water the best way is to drain and refill, but make sure your source water doesn’t have high calcium levels. We’d recommend having water trucked in for this.

Also, check to make sure your system has a zinc anode that is PLUMBED into the system. This prevents electrolysis – or the trace amounts of electricity conducted by salt water from damaging parts of your pool. Lack of a zinc anode could contribute to your issues.

Hope this helps – and thanks for the questions!