Alk problem

I periodically test Alk and found it was about 12. Let it drop to about 10. In the meantime I bought a new kit(salifert). The new kit shows it at 13. Tested at the same time. Both kits recently calibrated with the included fluid. Obviously one or both kits are off. Just not sure how to proceed. I could buy another kit but that could be different from both. Then which one to trust? Neither kits are near expiration (2019 for both). Other than not dosing Alk for a while (assume it is on the high side), I don't have a plan. Suggestions?

 

I would have your LFS test it for you also.
In my opinion the hannah checker has been the best for ALK(that I use). If you do the steps the same every time it is a consistent test. I have seen bogus reading a couple time but I am sure it was something I did(not enough reagent or something.

 

Hanna Checker all the way. I have the Salifert for Alk too. Usually I can match both up within a couple .10 of a point. Take the guessing out of testing for Alk. Since most hobbyist test for alk much more frequently get something reliable.

 

Thanks guys. I forgot about that option.

 

Recently bought the Hanna Alk Checker and love it so far. I have been able to test it against my Salifert and really close.

Are both kits you have Salifert? Do you have enough control solution to test both tests with it? If you can, this is what i would do to find the kit which is not performing.

 

How are you filling the Hannah checker vial? Are you eyeballing the line or are you using a graduated syringe? The latter being the better choice. Those lines are not always painted on with the highest tolerance of accuracy.

 

Calibrated the new kit and previously calibrated the old one a week ago. I ordered the Hanna, but I may go back and try to get to the bottom of it. Quite puzzling. I've got money on my testing technique being the problem. If one of them is off that far, that's a problem.

 

How long between tests? Any water changes done in that gap? Dosing anything?

 

What do you mean you calibrated it? How do you calibrate the Hannah?

 

He calibrated the salifert kit