what makes a hanna checker fail?

[Screwgunner]

I have had the same problem. Got a bad batch of regent. Witch hanna promptly replaced. Then I noticed like a white salt on my regent bottle . I would say get new regent . See if your shifts go away.

 

[smitten with ocean life]

thank you! ill look into that!

 

[Tcook]

I don’t have much experience with the Hanna alk tester. It’s hard to quantify if the checker is wrong or the reagent is; the latter is known to drift for some folks.

I significantly prefer titration methods for alkalinity.

The Hanna Alk kit fails verification—DIY Alk standards won’t work with it. You’re basically just trusting it works unless you compare it to a titration kit.

Which test do you use? Salifert?

 

[Miami Reef]

Which test do you use? Salifert?

Red Sea. It’s very accurate.