Dkh test stumped

[VanDalsenReef]

So I just received a new hanna alk (dkh) reagent and it showed my tank of 8.0 which is odd as I've been getting low 7's or even under 7. So I tested with a salifert alk test and got a 7.7
Went back and checked with my old hanna reagent (had some left over still) and it came back with 6.4.
Have I been off this whole time or should I try to find another way to test it to see what that comes to?
The older hanna reagent is not expired either but is very low

 

[VanDalsenReef]

The new hanna reagent reading and my salifert are both within the 0.3 error

 

[flyingscampi]

My Salifert usually reads .5 (or thereabouts) different to the Hanna. I would trust the new reagent over the old one. This thread might help:

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

Another tip I read for the KH is that you should only use the bottle for 25 tests and then discard the reagent.

 

[VanDalsenReef]

My Salifert usually reads .5 (or thereabouts) different to the Hanna. I would trust the new reagent over the old one. This thread might help:

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

Another tip I read for the KH is that you should only use the bottle for 25 tests and then discard the reagent.

Thank you. I actually ended up mixing new saltwater and testing it's alk. The hanna was spot on with tmp alk of 7.1. I'm guessing the old reagent was just bad at that point