Very strange pH and ORP readings

[serpentman]

I am getting very strange intermittent readings from my PX1000 (connected to my AC3). For some reason both drop to near zero for a while and then bounce back up. The temps read ok so it doesn't sound like a communication issue to the AC3. What gives?

Note: the ORP values are low as the probe needs to be calibrated.


Date Temp pH pH2 TmpA pHA1 ORPA
09:30 09/06/2009 78.8 7.95 6.55 78.5 8.08 329
10:00 09/06/2009 78.6 7.95 6.55 78.3 0.73 000
10:30 09/06/2009 78.4 7.95 6.55 78.4 0.73 000
11:00 09/06/2009 78.4 7.95 6.55 78.4 8.08 331

[kenargo]

Does this happen around the same time of day each day? My 1st suspicion is always some type of interference that nrmalizes after a while so if there is a pattern that would support this.

[serpentman]

It does seem to happen more at night. I'll try and check for consistency. Might be my heaters kicking on that's doing it.

[kenargo]

If you are running the newer firmware you might be able to review the XML Outlet Log and see if there are any overlaps. The Outlet log shows on/off times for all timers.