Hi, everybody.
I'm a new member of the forum.
I recently set up profilux 4 ultrimate set and now I'm commissioning and programming the system for my 600L sps reef tank.

I have an extension board of PL-0871 (PLM-pH/ORP-2 level) installed and it was working showing pH 2 (levels are not used yet).
It is intended to control my calcium reactor and was measuring pH 6.8x in the probe protection cap.
Couple of days ago, I calibrated it and installed in the calcium reacrtor without CO2 supply.
The measurement was slightly different from that of pH 1 but it was OK.

Next morning the pH 2 is disappeared from Profilux Touch diplay.
I checked Profilux 4 settings, Extras > Disply and Sesor Settings > Clibration, but there in no pH 2.
I put power off and connected a new pH probe and power on, but still there is no pH 2 on Display neither on Sesor Settings.
Could you anybody help how th resolve this problem?
Bad hardware or wrong setting?
What action can I do ??? Please help.

Son from Seoul Korea