Ph Dropping

[Ademster]

I calibrated the ph probe today using 7.0 and 10.0 calibration fluid.
The reading constantly drops.
Started off at 8.2 and continued to drop currently showing just above 7.0.

I tested with my liquid test kit and it shows 8.2-8.5

whats going on?

[rimai]

I was looking at the history of your controller.
It seems it was good for an hour or so and something changed at 9:30pm.
Do you remember doing anything at that time?
Does anything turn on at that time?
Can you check your float switches?? Maybe the exposed leads are touching the water?