Ph probe

[myprofilux]

Good day all,

I need some help understanding something. I calibrate my probes every 3months. I was calibrating my PH probe and this time I used solutions of 4.0 and 7.0. I usually use 7.0 and 9.0 however I ran out of this solution.

Lets say my tanks ph value was 8.1 before calibration.

I cleaned containers with RO for the ph solution and started the calibration process with 4.0 and 7.0.

Everything was a success and put the probe back into the tank - the probe after 30mins settled on 11.3 ph which is impossible.

I then recalibrated and got 10.2. I web out and bought 7.0 and 9.0 solution. Recalibrated and the result was a PH value of 7.6 ....

The probe is 6 months old .....


I don't know where to go from here any help?

If I do a color triation test I get 8.1ph ....

[GHL Support]

After calibration, does the sensor show the correct value in the calibration fluids?

[myprofilux]

After calibration, does the sensor show the correct value in the calibration fluids?

What happens is the following:

If I put the probe back in 9.0 the value changes every second from 8.85 to 9.15 it's constantly changing.

If I put the probe in 7.0 it goes down to 3.0 and stays there on 3.0 on the dot.

I have tried calibrating with 4.01 and 7.0 and I get the same on the high range it changes every second on the low range it goes to 3.0.

[Antipodes]

Sounds like the probe is damaged, possibly cracked the glass of the sensor??? (Still would not account for being semi accurate at top range.
Try your spare probe, (you have a spare sitting there for this sort of problem don't you)

Other thing to try is just do a full reboot, it is a computer after all. Pull the plug and restart and see if that changes anything.

Also what are your ADC values in the sensor screen for the PH probe.

[myprofilux]

Sounds like the probe is damaged, possibly cracked the glass of the sensor??? (Still would not account for being semi accurate at top range.
Try your spare probe, (you have a spare sitting there for this sort of problem don't you)

Other thing to try is just do a full reboot, it is a computer after all. Pull the plug and restart and see if that changes anything.

Also what are your ADC values in the sensor screen for the PH probe.

So rebooted the system - No Change

Inspected the probe - Look perfectly fine (actually only a month or so old)

ADC values:

ADC 1: 909
ADC 2: 901
Value 1 PH: 4
Value 2 PH: 7

What does ADC values mean (so I can undertand)

Also whats witrh the "Signal filter"

[myprofilux]

With my spare probe I have it in a different PH probe and I am getting SUMP PH: 7.71. (LOW!!)

The wierd thing - If I use calibration fluid with probe it reads the RIGHT values. HOWEVER if I do a simple color test (Red Sea Pro) I get a 8.2 PH reading???

ADC Values:
ADC1:379
ADC2:185
PH Value 1: 7 PH
PH Value 2: 9 PH

[Antipodes]

So rebooted the system - No Change

Inspected the probe - Look perfectly fine (actually only a month or so old)

ADC values:

ADC 1: 909
ADC 2: 901
Value 1 PH: 4
Value 2 PH: 7

What does ADC values mean (so I can undertand)

Actually NO these are not fine.
Below are my values and as you can see there is a good difference between the 2 values.
Also both are on the top end of the scale, which is just wrong.
Have you tried swapping your two probes positions and see if it also shows these parameters.

Also where is each probe going to. ie Profilux 3eX standard PH port. Additional port on add on card in which slot? Or an extension box? Which would make it a PAB unit?

I am not 100% sure, but I believe they are the raw values coming of the probes (i.e. MilliVolt). Only GHL can tell you for sure.

Antipodes ADC Values:
PH Value 1: 7 PH ADC1:502
PH Value 2: 10 PH ADC2:184

Don't take too much from my values as each probe is different.

Also what's with the "Signal filter"

Some probes have a very fast read time and the figure coming of them would bounce up and down showing a slightly different figure all the time like 8.65 then 8.7 and back again all the time. The signal filter takes that raw data and samples it by dividing by the amount of samples. And out puts that to the screen, thus giving a more stable reading. You can back it off a bit and try it, and if the figure is stable, then leave it there. I have played with all my probes and find the initial configuration of 5 is good.

With my spare probe I have it in a different PH probe and I am getting SUMP PH: 7.71. (LOW!!)

The wierd thing - If I use calibration fluid with probe it reads the RIGHT values. HOWEVER if I do a simple color test (Red Sea Pro) I get a 8.2 PH reading???

ADC Values:
ADC1:379
ADC2:185
PH Value 1: 7 PH
PH Value 2: 9 PH

OK not sure on what to think here. I keep a PH pen here for emergency purposes for comparison if anything seems out of whack.
Check for stray voltage on your tank. If it is reading right out of the tank and in the buffers. (Good new buffers I presume).

A while ago, a guy was getting erratic and erroneous readings from a light fitting.

Try taking a sample of water out of the tank and measuring it, then use your red sea to see what sort of difference there is.
Take a sample of water too your local fish shop or friend. See if they can measure if with a calibrated probe! Once you have a definite known water quality, you can better define what the issue is? (Or if it is even the profilux)

All seems strange that you were going along normally and then this happened without and changes.

Sorry that's all I have for you! Bit hard to see what is happening from 11,000 miles away. (assuming you are in LA)