Verify Probe Accuracy Using the Probe Calibration Testing Solution:

If values do not match; verify probe readings with a Probe Calibration Verification Test.

Look to see which side of the spa the probe is located; from inside the spa cabinet, remove the probe from the spa shell to dip into PH Calibration Verification Solution.

Add solution to the cap. Do not dip probe directly in the bottle.
Dip the probe in the cap of the 4.0 calibration solution.
Check the actual reading through the spas topside with the probe in the solution.
Press and Hold Pump 1 until InFo displays.
Press Pump 2, scroll until Sb displays.
Press Yess Button to display PH value.

This probe was dipped into the 4.0 solution; the reading on the topside shows 4.26 which is a good reading (+/- 10% is fine)

Dip the probe in the cap of 7.0 calibration solution.
Check the actual reading through the spas topside with the probe in the solution.
Press and Hold Pump 1 until InFo displays.
Press Pump 2, scroll until Sb displays.
Press Yess Button to display PH value.

Does the probe read 4.0 +/- 10% or 7.0+/- 10% respectively?

Complete a Probe Verification Test BEFORE Changing the Probe