pH probe issues

[Joe_Blog]

The pH probe is two years old, but still "brand new" as it has been in storage until I was able to set my tank up recently. I am trying to calibrate/use the probe, but having problems. I've followed the advice given many times on here about calibration and all seems to be good with that. However, no matter how many times I calibrate, I still get a reading of 10.5 pH no matter where I place the probe, e.g., in the tank, in the 7.0 calibration fluid, or in the 9.0 calibration fluid. Is my probe "old" or faulty and thus need a new one or am I doing something wrong?

Thanks for the help!

 

[Antipodes]

Sounds strange, but if you want you can come and test it on my Profilux to see if it is the probe or another issue.
I also have another probe here to try on yours if it proves the probe is defective when you test it here!
PM sent.

 

[AQD_ottawa]

Even when stored probes will degenerate, its is due to the breakdown of the reference junction, leaving it in storage is the same as using it, so the expected life should be from 12 months to 18 months.

The storage solution stops the reference junction drying out but it will not stop it from degenerating. We do regularly advise pre sales clients that stocking up on probes is a false economy, buy when you need to and not before.

 

[Joe_Blog]

Thanks for that. I also have temperature, Redox, and humidity probes. Do you think that all these are past their expected lifespans as well? I just installed and calibrated the Redox probe tonight and so far so good. The temp probe seems to be all out of whack though with readings of 22C when the tank is pushing 30C! :eek1: Good thing it is only cycling at the moment. I haven't yet figured out how to use the humidity probe.

 

[AQD_ottawa]

Temperature - if looked after indefinate life

Redox - If cleaned every 3 months should last 2 years, but as with pH probe degenerative hense limited warranty so best practice to look after it.

Salinity - as with Temperature

Humidity - If kept out of dirt indefinate.

Cleaning - mild soapy water and wipe platinum tip with tissue.

Redox will take a good two weeks prior to reading correctly from new this is normal and documented on here.

Wrong Temp reading - Has ProfiLux been upgraded from plus II to P3 if so were the original ADC values recorded and re inputted?

Has the calibration been played with?

Possible correct reading and other device way out - But this is normally seen as a few degrees not 8 degrees

Unplug temp probe and re insert it.

If still experiencing off reading and none of the above applies ask your retailer to test it, but to date I have never seen a single ProfiLux produce such a fault and neither the probe just for reasurance, it is normally an external force at work.