If you can calibrate your temperature probe - you probably should.

TinyChocobo · Mar 8, 2018

I checked my water temp next to my Apex Temp Probe with a NIST Certified +/- 0.4 Degree Fahrenheit thermometer as well as two other thermometers and came out with an average reading 1.5 degrees lower than the Apex was reporting.

I trust the NIST Thermometer to be closer than the Apex out of the box due to the NIST Certification that my thermometer carries [and is still valid].

This means effectively that when I had set my aquarium to run at 78 degrees it was really running 76.5 which is a bit on the low side.

Granted I'm likely still not exactly 100% accurate - but I'm going to be much closer than I was. I turned down my temperatures a bit and will up the temperature from 76.5 to 78 over the next 12 hours or so as not to have a sudden change.

TinyChocobo · Mar 8, 2018

That said... the calibration of the PH probe uses the temperature probe... I'm thinking the calibration of my PH probe is likely off at this point...

TinyChocobo · Mar 8, 2018

Yeah 0.21 drop in PH reading by calibrating the temperature probe up 1.5 * F. Looks like I need to order some PH Solution.

justingraham · Mar 8, 2018

I have checked my tank with like ten different thermoters
three apex probes
one Mack for Ac ducts
one multimeter
one hand gun
Three glass ones
And my heater thermostat

None was the same all about a half degree difference so I don’t know what it is

But in all that
I’m more worried about the consistency

TinyChocobo · Mar 8, 2018

justingraham said:
I have checked my tank with like ten different thermoters
three apex probes
one Mack for Ac ducts
one multimeter
one hand gun
Three glass ones
And my heater thermostat

None was the same all about a half degree difference so I don’t know what it is

A half degree range is fine/good imho especially if they all report it. Everything *but* my apex was reporting 1.5 degrees lower than the Apex - not so great

.

justingraham said:
But in all that
I’m more worried about the consistency

This is true - but if I expect it to be 78, or 79, or 80 - I hope that it's at least within a half degree of that - not 1.5 degrees out!

madweazl · Mar 8, 2018

The difference to the inhabitants in regard to 1.5° would be nothing given your range so I wouldn't worry about it much. I suppose if you were at one extreme or the other in regard to temperature it could become an issue but with most people running 77-83°, it makes no difference to the health of the critters.

Out of curiosity, did you have multiple [Apex] probes reading the same temp?

TinyChocobo · Mar 8, 2018

madweazl said:
The difference to the inhabitants in regard to 1.5° would be nothing given your range so I wouldn't worry about it much. I suppose if you were at one extreme or the other in regard to temperature it could become an issue but with most people running 77-83°, it makes no difference to the health of the critters.

Out of curiosity, did you have multiple [Apex] probes reading the same temp?

I have just the one probe - my old set-up had more than one but this one I only have one on right now.

And yeah 1.5 isn't a huge difference - but I do prefer things to be as accurate as they can be [within reason].

Randy Holmes-Farley · Mar 8, 2018

TinyChocobo said:
That said... the calibration of the PH probe uses the temperature probe... I'm thinking the calibration of my PH probe is likely off at this point...

The temperature correction to pH is mostly important to adjust between the calibration temp and the measurement temp. A probe being off moves them both together so wouldn’t cause a problem.

Randy Holmes-Farley · Mar 8, 2018

TinyChocobo said:
Yeah 0.21 drop in PH reading by calibrating the temperature probe up 1.5 * F. Looks like I need to order some PH Solution.

The error is nowhere near that large. Where did you get that number?

TinyChocobo · Mar 8, 2018

Randy Holmes-Farley said:
The temperature correction to pH is mostly important to adjust between the calibration temp and the measurement temp. A probe being off moves them both together so wouldn’t cause a problem.

I planned on floating my calibration fluid in the sump and re-calibrating anyhow [as I didn't do that the first time].

TinyChocobo · Mar 8, 2018

Randy Holmes-Farley said:
The error is nowhere near that large. Where did you get that number?

A PH/Temp calculator.

Randy Holmes-Farley · Mar 8, 2018

TinyChocobo said:
A PH/Temp calculator.

You used it wrong somehow.

TinyChocobo · Mar 8, 2018

Randy Holmes-Farley said:
You used it wrong somehow.

I put in PH 7.8 and temperature of 78 and got one reading, then I changed temperature to 76.5 and then took the difference between the two outputs.

It's possible this wasn't a good way to go about it - I'm no expert at this for sure

.

Randy Holmes-Farley · Mar 8, 2018

It's a fine way. You must have done it wrong or used a bad calculator

https://www.hamzasreef.com/Contents/Calculators/PhTempCorrection.php

Actual value 8.100
enter 79.5 deg F: 8.0949
enter 78 deg F: 8.098

TinyChocobo · Mar 8, 2018

I just realized I typed my post wrong. I meant 0.021 not 0.21. Still had the calculator up on my laptop from when I did the math... Sigh

.

madweazl · Mar 8, 2018

Cant trick the Dr

TinyChocobo · Mar 9, 2018

My PH dropped according to the Apex to 7.79 last night causing it to alert me so that 0.021 did make at least a little difference

.

Waiting on my PH Fluid to show up.

Daniel@R2R · Mar 9, 2018

Interesting. I probably wouldn't be overly concerned about a 1.5* difference. Probably just adjust the tank temp accordingly. That small of a pH reading difference shouldn't impact livestock at all IMHO.

TinyChocobo · Mar 9, 2018

mdbannister said:
Interesting. I probably wouldn't be overly concerned about a 1.5* difference. Probably just adjust the tank temp accordingly. That small of a pH reading difference shouldn't impact livestock at all IMHO.

Nah the PH reading difference isn't going to affect anything but my Apex alerting me when it drops 0.01 below the threshold

.

And yeah 1.5* isn't going to kill anything - but I was a bit surprised to find it that far off.

Daniel@R2R · Mar 9, 2018

TinyChocobo said:
Nah the PH reading difference isn't going to affect anything but my Apex alerting me when it drops 0.01 below the threshold .

And yeah 1.5* isn't going to kill anything - but I was a bit surprised to find it that far off.

It's definitely good to know about the issue...and those pesky alerts would get annoying if you know they're because of a false reading.