Alk test kits .

[Rmckoy]

With many different kits for testing alkalinity . I’m not sure which one to trust .

salifert results 7.3dkh but using a syringe that might be from a old Red Sea kit

api kit that expires 2017 which results are 7 dkh ( drops )

Hanna 137ppm ( 7.62dkh ) started to test higher a few months ago but not sure to trust it or not but I think I might have found the testing error with a few numbers rubbed off , I was adding 0.9ml reagent

 

[gbru316]

I made an alk reference standard a few weeks ago and tested salifert, Hanna, and trident with it.

salifert was spot-on. Hanna was off by a few tenths, trident was significantly “off.”

I now use the trident for trend analysis and salifert for accuracy if I lose trust in the trident data. (And then I recalibrate trident using the salifert data). I’m not convinced that Hanna has a place in my process any longer.

 

[Rmckoy]

I made an alk reference standard a few weeks ago and tested salifert, Hanna, and trident with it.

salifert was spot-on. Hanna was off by a few tenths, trident was significantly “off.”

I now use the trident for trend analysis and salifert for accuracy if I lose trust in the trident data. (And then I recalibrate trident using the salifert data). I’m not convinced that Hanna has a place in my process any longer.

Hanna has proved to be inconsistent with their reagent .
possibly too many variables to go wrong

I’m going to order a new salifert kit .
along with a new battery for my Hanna checker and track their accuracy

 

[Spare time]

Just pick one and stick with it. The difference between them one matter. I wouldn't use the api as it doesn't give the precision needed for accurate dosing