This is what i have:
Sense and Dispense (HL-CHEM), Ph Dispense System (AQL-CHEM3)
I have it for one session, I came to trust the system in a way that i check FC once a week and PH once every 2-3 weeks just to double check the probes are doing their jobs.
So far no issues, it keeps the PH at 7.5...