Hannah Dkh Checker Showing Impossible Results? Or is it?

madweazl · Dec 17, 2019

Juka087 said:
Maybe I should get a 1ml volumetric pipette with a freaking pipette vaccum.....all to find out the checker is incorrect anyway.

There is no need to use anything but the included syringe; this is how all syringe work with a tip on them. The checker is quite accurate (not sure who made the .5 dKh error comment but that is incorrect).

Juka087 · Dec 17, 2019

madweazl said:
There is no need to use anything but the included syringe; this is how all syringe work with a tip on them. The checker is quite accurate (not sure who made the .5 dKh error comment but that is incorrect).

I figured out just now I've been using the syring wrong. I though the tip WAS volumetric. So I was using the entire syringe to fill the tip -,-

Silent · Dec 17, 2019

That will give inaccurate readings. Good catch.

Juka087 · Dec 17, 2019

Silent said:
That will give inaccurate readings. Good catch.

-,-

NeonRabbit221B · Dec 17, 2019

I used this for a month before realizing I had been reading syringes wrong for over 1+ years... Was reading from bottom tip of the plunger. *Shrug*

Juka087 · Dec 17, 2019

NeonRabbit221B said:
I used this for a month before realizing I had been reading syringes wrong for over 1+ years... Was reading from bottom tip of the plunger. *Shrug*

How are you supposed to read it

NeonRabbit221B · Dec 17, 2019

At the line. The tip of the plunger displaces the air in the syringe.

Coastie Reefer · Dec 17, 2019

NeonRabbit221B said:
At the line. The tip of the plunger displaces the air in the syringe.

The tip adds the air gap... you're supposed to read the bottom of the plunger and ignore the air gap.

NeonRabbit221B · Dec 17, 2019

Sorry I am terrible at explaining. Here is a picture

mike550 · Dec 17, 2019

Stepping back a bit. Hanna says their dkH meter is accurate +/- 0.3 dkH or 5%. So a slight variance between two tests shouldn’t be surprising.

I’m new to the hobby, and a lot of folks have told me don’t try to manage to the numbers. So I measure dkH to monitor and give me a sense of the numbers but I’m also watching for sudden changes or trends.

What do I gain by knowing my dkH to better than 5% accuracy, and how much does a tank benefit for example from knowing dkH to 3% accuracy?

Juka087 · Dec 17, 2019

Coastie Reefer said:
The tip adds the air gap... you're supposed to read the bottom of the plunger and ignore the air gap.

When I use the tip with the syringe. It only fills the tip never any in the syringe even if I use the entire syringe.

Coastie Reefer · Dec 17, 2019

NeonRabbit221B said:
Sorry I am terrible at explaining. Here is a picture

Considering the Hanna supplied syringe is completely flat, this is a non-issue.

Coastie Reefer · Dec 17, 2019

Juka087 said:
When I use the tip with the syringe. It only fills the tip never any in the syringe even if I use the entire syringe.

This was only an example... the principle is still the same, just a larger air gap.

Silent · Dec 17, 2019

Check out the 15 min mark. Perfect instructions from hanna.

NeonRabbit221B · Dec 17, 2019

Coastie Reefer said:
Considering the Hanna supplied syringe is completely flat, this is a non-issue.

Mine is actually not flat at all. It has an air displacement dip which is odd. I was filling it to the "don't read here mark" every time for every test for about a year. If that is not proof that consistency over changing numbers is critial idk what is haha

PigFarmer · Dec 17, 2019

My Hanna DKH checker changes with every regaent bottle... Last week I bought 3 bottles of reagent. all 3 of them read differently. they were all within .5 of eachother with back to back to back tests but all 3 read differently. my checker reads the 5.0 calibration viles as 5.1. Hobby grade but you can still see how your ALK is trending with the inconsistent reagents. Best practice I have found is when you run 1 reagent bottle dry.. open your next bottle right away and do another test to see how far it is off from the old bottle so we can form some information in our heads.

Juka087 · Dec 17, 2019

PigFarmer said:
My Hanna DKH checker changes with every regaent bottle... Last week I bought 3 bottles of reagent. all 3 of them read differently. they were all within .5 of eachother with back to back to back tests but all 3 read differently. my checker reads the 5.0 calibration viles as 5.1. Hobby grade but you can still see how your ALK is trending with the inconsistent reagents. Best practice I have found is when you run 1 reagent bottle dry.. open your next bottle right away and do another test to see how far it is off from the old bottle so we can form some information in our heads.

With how annoying this hannah checker is. It gives me appreciation for the hach gear I am using right now. I am literally a water treatment operator. I guess that's why this makes me so angry.

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Coastie Reefer · Dec 17, 2019

NeonRabbit221B said:
Mine is actually not flat at all. It has an air displacement dip which is odd. I was filling it to the "don't read here mark" every time for every test for about a year. If that is not proof that consistency over changing numbers is critial idk what is haha

I've bought dozens of reagents and every syringe included has been flat... are you sure you're using the one that came with the reagent? Also, there's nothing odd about the air gap. Nearly all syringes will have a small gap with or without a tip.