Hanna checker vile...?

[legrunt]

I have 3 test kits, HI772, HI758 and HI774. All purchased this year. All the vials show exactly 10ml.

 

[92Miata]

Hanna a reagents are horrible

Have to say I’ve had zero issues with the Alk test. Calcium that’s another story. That Just doesn’t work well.

www.reef2reef.com

From another thread - two Hannah vials with the lines at different heights.

Use a syringe.

 

[legrunt]

Do you have older vials?

I use a syringe to fill mine now, and if I had to guess, I'd put the line at about 8.5 ml.

Either Becton-Dickinson is wrong, or my Hanna vials are. (Vials from ulr phosphate)

Do you have a high precision scale? Since we are talking about 10ml, and not venturing into ul territory here, you might get away with a scale that shows grams up to 1 decimal point. Weigh the amount of water and it should come very close to 10grams. (should actually be ever so slightly below 10grams, to account for z factor of water temperature)

 

[reefiniteasy]

Don’t trust the cuvettes. Use a syringe.

 

[legrunt]

Hanna a reagents are horrible

Have to say I’ve had zero issues with the Alk test. Calcium that’s another story. That Just doesn’t work well.

www.reef2reef.com

From another thread - two Hannah vials with the lines at different heights.

Use a syringe.

Wow, that's quite the discrepancy in height levels!
Now, we can assume one of two scenarios from that picture. Hanna QC sucks big time, or they are actually pretty good.
If the volume is wrong, it would mean they suck. If however, they mark based on actual volume, due to vial diameter discrepancy, or even wall thickness discrepancy, then they might be actually quite good. Only way to know would be to gravimetrically test both vials.

 

[legrunt]

Anyway, with repeated wipes to ensure the surfaces are clean and dry before going into the checker, I find that only after a few months, the markings start to come off. I'm sure within a year, I wouldn't have the mark there anymore.

 

[92Miata]

Wow, that's quite the discrepancy in height levels!
Now, we can assume one of two scenarios from that picture. Hanna QC sucks big time, or they are actually pretty good.
If the volume is wrong, it would mean they suck. If however, they mark based on actual volume, due to vial diameter discrepancy, or even wall thickness discrepancy, then they might be actually quite good. Only way to know would be to gravimetrically test both vials.

Or, I can just assume that the company that makes billions of syringes a year and is subject to heaploads of regulation in basically every country in the world is doing an ok job.

You can buy vials from Hannah for $2 a piece. They're not individually testing and marking them.


In the grand scheme of things, it probably doesn't matter, because the tests are basically +- 10% or more in the ranges were testing.

 

[legrunt]

I guess you're right. Anyway, like I said, in the near future, I won't have anymore markings on the outside of my vials with the repeated wipings... so yeah.

 

[Broutilde]

Are you sure? I have switched over to air displacements pipettes, which I have calibrated myself gravimetrically using a milligram scale. They dispense to exactly the 10ml mark. Remember, bottom of meniscus. Not where the water meets the sides.

I'm pretty sure, I ended up weighting the water on a high precision scale :/

 

[Sisterlimonpot]

I can understand where that misconception may come from. Example, the calcium checker. You're supposed to put 1ml of reagent into the vial, and then fill it up to the 10ml mark with pure water. Meaning 9ml of pure water. But then some people think they should be adding 10ml, and end up past the line.

And also some people are not aware that you are supposed to be reading the 10ml line at the bottom of the meniscus. Not where the water meets the sides of the vials.

FWIW, my 10ml syringe dispenses exactly at the 10ml mark, bottom of meniscus.

I don't use the hanna calcium tester, I have one but it's on a shelf in a cabinet in the garage.
But you made me go and read the instructions for alkalinity, because I was afraid that I was doing it wrong this whole time. Found out that the final solution to be tested is 11ml.

The 9ml water +1ml reagent must only be for calcium.

 

[AZReef13]

During on of BRS videos about test kits, they said use syringe and fill to line... about 26 minutes in

 

[legrunt]

I don't use the hanna calcium tester, I have one but it's on a shelf in a cabinet in the garage.
But you made me go and read the instructions for alkalinity, because I was afraid that I was doing it wrong this whole time. Found out that the final solution to be tested is 11ml.

The 9ml water +1ml reagent must only be for calcium.

Correct...
Cal is 1ml reagent liquid + 9ml purified water for C1, then 0.1ml sample + reagent powder for C2.
Alk is 10ml sample for C1, then 1ml reagent liquid for C2.

 

[mavbarnby]

I use a syringe because eyeballing the cuvette is tedious to say the least. If you're eyeballing it, you fill so the meniscus of the water (the lowest point of the concave top of the water) meets the line (the edge of the water in the cuvette will be over the fill line).

So you fill so the meniscus touches the bottom of the cuvette line? Not to the top of the line? I keep getting inaccurate readings and I feel like it’s due to inaccurate amount of water