Ph probe readings erratic

[Joshd]

I have two ph probes connected to the hydros, one reads the tank display and the other controls my calcium reactor. The reading of both go crazy at random times way high. Today i have finally narrowed it down to the gyre xf330 controller. Any ideas if the controller is bad? Or is this just intereference that needs to be remedied somehow?

 

[John Neuzil]

I don't know the answer but the lights on my Icecap Algae reactor do the same thing to my pH readings.