What is my ACTUAL pH?

[copi]

I have 2 pH probes... both calibrate perfectly. After calibration, if you place the probe into a pH 7 reference, both read 7.0 on the dot. Same for pH 4 reference and pH 10 reference.

I also have the Hanna pH checker and the Salifert pH test kit. The Hanna checker returns a perfect result with their reference solution. The Salifert test I have not attempted to validate.

In my aquarium, both probes read somewhere around 7.8 . The checker and Salifert kit both read 8.1.

Which should I believe?

 

[Icryhard]

I am guessing margin of error. Take the average of those values I'd say.

 

[Randy Holmes-Farley Verified Community Expert]

I have 2 pH probes... both calibrate perfectly. After calibration, if you place the probe into a pH 7 reference, both read 7.0 on the dot. Same for pH 4 reference and pH 10 reference.

I also have the Hanna pH checker and the Salifert pH test kit. The Hanna checker returns a perfect result with their reference solution. The Salifert test I have not attempted to validate.

In my aquarium, both probes read somewhere around 7.8 . The checker and Salifert kit both read 8.1.

Which should I believe?

What does the Hanna read in the pH 7 and 10 calibration fluids?

What do you mean their "reference" solution?

 

[copi]

What does the Hanna read in the pH 7 and 10 calibration fluids?

What do you mean their "reference" solution?

Hannah Checker won't read the 7 and 10 calibration fluids, I believe, because they're colored.

Hannah sells a vial of known pH that you can use to confirm accuracy of the checker

HI780-11 Marine pH Calibration Check Set

Easily calibrate and test proper functionality of your Hanna Checker HI780 Marine pH Colorimeter. Contains Standard A and Standard B Follow instructions in packaging Includes certificate of analysis Reuseable with long shelf life Hanna Checker Instructions for Marine pH Calibration Check...

www.bulkreefsupply.com