Using hanna checkers

[cilyjr]

Whenever I use hanna eggs(not for the big 3), I always run the test 3 times.

For sake of ease and not doubling reagents, I do it in an unconventional way.

First, I fill each vial with 10 mil water using an oral syringe.
then, 1 with reagent. Fold the envelope in half so it has a crease down the middle diagonally.
Then I cut the opening with a razor. The crease allows you to easily pour the powder into vial.
Next, I use the water only vial for c1 portion and the reagent vial for c2.

1st test I let it do its full count down, 2nd test I force an immediate read.
Then I take my three results and average them.

I get pretty differing results, especially from the phosphorus test.

 

[carri10]

A first point. The Hanna Egg uses light adsorption to measure the levels of the thing being measured. Now, imagine one vial is dirty and no light goes through it. Another vial is completely clean on the outside. The first would adsorb all the light, the second would adsorb none. They would give different results regardless of what happens inside the vial. This is an extreme case of why you should use the same vial for blanking (the C1 part) as the measuring (the C2 part). Using different vials could make a difference, as light might not go through them in an equivalent way..
Next thing is the count down. Alsways use the countdown if insatlled, as the chemicla reaction sometimes takes time. Phosphorous is a good example.

Sorry if this is insultingly basic, not sure of your analytical chemistry level or my reading comprehension level!

 

[cilyjr]

A first point. The Hanna Egg uses light adsorption to measure the levels of the thing being measured. Now, imagine one vial is dirty and no light goes through it. Another vial is completely clean on the outside. The first would adsorb all the light, the second would adsorb none. They would give different results regardless of what happens inside the vial. This is an extreme case of why you should use the same vial for blanking (the C1 part) as the measuring (the C2 part). Using different vials could make a difference, as light might not go through them in an equivalent way..
Next thing is the count down. Alsways use the countdown if insatlled, as the chemicla reaction sometimes takes time. Phosphorous is a good example.

Sorry if this is insultingly basic, not sure of your analytical chemistry level or my reading comprehension level!

I thought about that at one point. When I ended up talking to Hanna about it, they didn't think it would make much difference.

 

[arcangelreef32]

Nothing really unconventional about how you're doing it. From reading many posts here and elsewhere over the years, a lot of people use the Hanna's similar to what you're doing.

Biggest thing is just to make sure the vials are clean and not scratched up too bad.
I rinse mine with rodi after every use, and i clean them with water and microfibre cloth making sure there are no fingerprints or anything on the vials before i perform the tests.

The length of time the reagent sits in the test could possibly make a difference as well. They have set times for a reason. Its possible that could be affecting the results when performing multiple tests on the same reagent added water.

I tend to just take the first number it gives me and go with that.
Anytime i send off an ICP I do a battery of tests myself the same time i prep the sample.
My numbers are generally very close to what comes back with the icp.

 

[Dan_P]

Whenever I use hanna eggs(not for the big 3), I always run the test 3 times.

For sake of ease and not doubling reagents, I do it in an unconventional way.

First, I fill each vial with 10 mil water using an oral syringe.
then, 1 with reagent. Fold the envelope in half so it has a crease down the middle diagonally.
Then I cut the opening with a razor. The crease allows you to easily pour the powder into vial.
Next, I use the water only vial for c1 portion and the reagent vial for c2.

1st test I let it do its full count down, 2nd test I force an immediate read.
Then I take my three results and average them.

I get pretty differing results, especially from the phosphorus test.

The Hanna vials seem to be interchangeable, using one as a blank to perform multiple readings can work. I use this method but confirmed my blank vial was indeed interchangeable with the sample vial. The multiple readings of the same test sample averages out the variation in the Checker performance.

 

[cilyjr]

The Hanna vials seem to be interchangeable, using one as a blank to perform multiple readings can work. I use this method but confirmed my blank vial was indeed interchangeable with the sample vial. The multiple readings of the same test sample averages out the variation in the Checker performance.

That was my thinking, thanks

 

[awokenreefboy]

There are a few things that are tricky with the Hanna Checkers. My biggest advice from personal experience is to ALWAYS throughly clean your vials/pipets/syringes with soap, water, and finally RODI water. Especially with the calcium test I was getting MULTIPLE 100+ppm readings from freshly made saltwater, but as soon as I throughly cleaned out all the equipment I was consistently getting accurate results.

Another thing is watching the videos they have on YouTube. I can’t tell you how many times I’ve seen people having problems when they didn’t follow instructions. For example, the 10mL should be measured with a separate syringe to ensure accuracy every time, or at least measure from the bottom of the meniscus. Another example would be from the calcium test. It says to put in 1mL of reagent A and then fill the vial to the 10mL with RODI. Many people will put in the 1mL of reagent and then put in 10mL of water instead of the correct 9mL (1mL reagent + 9mL water = 10mL line).

 

[Miami Reef]

I do it the same way as OP. It’s very easy to keep the vials clean and clear.

I too preform 3 trials with the 2 vials.

 

[KrisReef]

The story i heard about the Phosphorus test, and reading the instructions after zeroing the first vial, remove and add the reagent.

Shake for 2 minutes (I usually just shake it a minute, but wait the full two) before hitting the 3 minute timer, for a total of reagent wet for 5 full minutes before the sample is read.

The reason was that the best color development for the Checker to read took the full 5 minutes for optimum results.

I usually measure only one time unless I get weird results and then I retest (for any of the checkers) to make sure I believe the results, or to make certain I messed up the 1st time, or not.

Using a 10 ml syringe, wiping the vial and not touching it with my hands to keep oil off, and carefully placing it back in the checker in the same alignment, and using the timer for phosphate allows me to get repeatable results for P & Alk, the two I generally use to monitor with.

I swear to Hanna I wish I lived next door to an ICP lab. That would be better than waiting for the timer and rinsing vials, and stuff.

 

[Patx]

I use a digital scale (10gram) for the 10ml.
Same for the ALK test... 1ml-1gram regent...

 

[KrisReef]

I use a digital scale (10gram) for the 10ml.
Same for the ALK test... 1ml-1gram regent...

You probably get great repeatable results if the scale is precise but 10ml of pure water does not = 10 grams of saltwater (SPG 1.025)

The irony is that if your parameters stay solid the numbers are ok if they are also solid.

 

[Patx]

You probably get great repeatable results if the scale is precise but 10ml of pure water does not = 10 grams of saltwater (SPG 1.025)

The irony is that if your parameters stay solid the numbers are ok if they are also solid.

Exactly, it's good to clarify.

But I don't bother with this detail.
For the weight of 1ml alk regent too. Etc...
But in the end the results are very stable and reliable.
I start the 2 min. timer as soon as I open the bag.
(I got the weights of the powder too lol)
Also note that the vials do not all have the same weight.