Ph probe swing

[Brandon]

I have calibrated my ph probe several times now and are having problems with the value jumping all over the place. When i calibrate the probe it doesn't say there is a problem with the calibration, when it's finished cal. I save and test the probe in the cal. solution and the value is no correct and swing heavily. My probe cords do not run by power cords and away from ballasts. any suggestions?

[Brandon]

I placed the probe back in water and after a while the ph reading drops to about 3.0+/- everytime I ahve calibrated it.???

[Matthias]

if the probe doesn`t show a reasonable value when immersed in the calibration fluid after a calibration then a defect may be considered.
Maybe it is only a broken cable or a bad contact in the plug and you can repair it.

[Brandon]

I have checked the connect more than ounce and the probe is new with my profilux. Never showed reasonable value. Neverless will check conn. and cable one more time after post. What to do then?

[Matthias]

a brand new probe which is defective ? - ask your retailer for replacement

if you are able to check or even to replace the BNC - then do this

[BrunoW]

I placed the probe back in water and after a while the ph reading drops to about 3.0+/- everytime I ahve calibrated it.???

I had the exact same problem.... and I tried with 2 different electrodes that both read correct on other controllers (and 1 of them where also brand new) and after a couple of support e-mails back and forth with GHL they came to the conclusion that my controller had a defect.

So I had to return it GHL for repair, but as I couldn't just unplug the controller since it was controlling basicly everything on my tank I just left the electrode in the tank while figuring out what to do......

Then after aprox a month time I was just sitting around looking at my tank and just decided to try to recalibrate the controller again....... and to my surprise it worked again and has now done so for aprox a couple of months

[aqua_digital]

New probes sometimes can take a while to settle down, the reason for this is that the storage solution penetrates the membrane and blocks it.

To over come this soak the pH probe in 4.0 calibration for 24 hours to relieve the blocked membrane. The other way as the post above shows, the membrane in time will unblock itself but can be a slow process.