Hanna Alk checker question

[Cpage101]

I know we have all grown to love the Hannah all checker here. Has anyone else ever purchased the certified hannah ALK test check kit? I was questioning my #’s between my trident and the hannah and they seemed to be quite a bit off so i figured WTH i’ll order and see what the accuracy is. So the instructions say that the test sample is 100 ppm and that test should be between 90 and 110 with the +\-5% noted accuracy. I have always assumed 10% +\- because they are hobby grade. So when I just tested btw the test bottles have been in the living room so they should be somewhere between the recommended 25C temp. This fam thing is testing an additional 10% lower than it the instructions note. Tell my your experience if you have purchased this accuracy testing kit HI755-11 for alk tester.#hannainstamentsstruggle

 

[Errol]

The only time I ran into trouble (although I didn’t approach it as scientifically as you) was when I came to the end of the alk additive solution. When I added new solution it seemed to read correctly.

Also, I was instructed to mix the solution by inverting the tube a few times, not shaking it as bubbles can affect the reading. You may well know that already.

 

[BiGGiePauls33]

No experience here. It have read somewhere to keep the reagent in the refrigerator as it tends to not be as accurate as time goes on

 

[Skmaiden]

I’ve found that old reagent tends to read low.

 

[Cpage101]

I’ve found that old reagent tends to read low.

brand new bottle of reagent this is the hanna testing set for this tester

 

[Chlorinated]

The Hannah Alk reagent degrades with time if kept an room temp. I know from personal experience.

I was using an old bottle stored at room temp and within exp date....and testing at 7 but my tank looked like crud. Bought a new bottle and 16! I confirmed against Salifert and it was off the charts.

Over the last 2 years I have purchased multiple new bottles and kept some old ones in the refrigerator for comparison. Kept in the refrigerator for 18mo...6mo past exp, and testing right on with new reagent. Cold is key!

 

[MichaelJ]

I put a new box of reagent in fridge last night, tested with old reagent (3 to 4 months old) 8.2. New reagent (refrerated) 8.1. So I don’t know if putting it in the fridge matters, I do think overly outdated regents matter.
Salinity 1.026

 

[BiGGiePauls33]

I put a new box of reagent in fridge last night, tested with old reagent (3 to 4 months old) 8.2. New reagent (refrerated) 8.1. So I don’t know if putting it in the fridge matters, I do think overly outdated regents matter.
Salinity 1.026

How much reagent in the older bottle, I read that as it dwindles towards the bottom is when it gives inconsistent readings

 

[MichaelJ]

How much reagent in the older bottle, I read that as it dwindles towards the bottom is when it gives inconsistent readings

Older bottle that was not refrigerated is 1/2 full….when I put my syringe in, it goes to the bottom……but I softly shake the bottle each and every time in case anything is settled.

 

[GobyWanKenobie]

I noticed the last two or three tests in the bottle were lower too. I never thought about refrigeration. Thanks for the idea.

I'm striving for consistency. As long as the tank isn't dying, I just aim for the same number, usually 155-160.