Hanna Dkh reagent life span

[m.kristoff]

I have read several places that Hanna reagents loose accuracy over time. does it tend to drift up or down with readings?

 

[javisaman]

tends to drift down. I always swirl the bottle before I draw the reagent and found that tightly closing the top immediately after help. Usually after opening it stays the same for about 2 months, but then if I were to compare it with a new bottle it reads slightly lower. I have the alk measure in ppm and it's usually around 10 (0.55) ppm less. But I've seen it be as different as 50 ppm (2.5 dkh).

 

[Randy Holmes-Farley Verified Community Expert]

This thread is worth a read:

Important findings according how to store open bottles of the reagent for Hanna Marine alkalinity checkers

There is a way to hinder the Hanna alk to show lesser and lesser dKH (or ppm for that matter) with age of open reagent bottle. I had the same story as many have reported here - my reading decrease from a new open bottle with time. Double check with another method show that there was not a real...

www.reef2reef.com

 

[m.kristoff]

tends to drift down. I always swirl the bottle before I draw the reagent and found that tightly closing the top immediately after help. Usually after opening it stays the same for about 2 months, but then if I were to compare it with a new bottle it reads slightly lower. I have the alk measure in ppm and it's usually around 10 (0.55) ppm less. But I've seen it be as different as 50 ppm (2.5 dkh).

thanks. I am getting some weird reading
Alkatronic- 9.04
Hanna reagent 1- 9.1. It i just over 2 month old
Hanna reagent 2- 9.4. I t is about 2 months old. it was spot on with the alkatronic

I tend to believe my Alkatronic. just recalibrated its pumps to be sure

all within +/- but wondered what the drift over time was.

 

[m.kristoff]

This thread is worth a read:

Important findings according how to store open bottles of the reagent for Hanna Marine alkalinity checkers

There is a way to hinder the Hanna alk to show lesser and lesser dKH (or ppm for that matter) with age of open reagent bottle. I had the same story as many have reported here - my reading decrease from a new open bottle with time. Double check with another method show that there was not a real...

www.reef2reef.com

thanks! great info