Can you operate the Hanna ALK checker incorrectly?

[NewbReef]

Yesterday I got myself myself my first Hanna checker and the result was a lot higher than my colour chart readings.

I done 3 colour readings with API that all came out at 8.3 but my Hanna checker was 9.1!

Is it more likely that I consistently use the API kit incorrectly rather than the Hanna?

 

[rtparty]

The API is likely inaccurate but consistent is better than accurate for our use (as long as the accuracy is close enough.)

 

[AydenLincoln]

Yes you can! But I would trust the Hanna Checker not API. You want to make sure the vial is completely clean and free of any debris/fingerprints both inside and out (rinse with RODI water and wipe it off with a towel) and you add in the you right amount of reagent. I’ve made these mistakes before with other checkers and gotten false results.

 

[NewbReef]

The API is likely inaccurate but consistent is better than accurate for our use (as long as the accuracy is close enough.)

Yeah that's what I was thinking! Especially as at the moment I'm trying to figure out how much to dose of all for reef.

Just tested again with the Hanna, made sure everything was nice and clean and it came out as 7.7, so tried the API again at 8.3

I will just keep trying until I perfect it, I guess!

Yes you can! But I would trust the Hanna Checker not API. You want to make sure the vial is completely clean and free of any debris/fingerprints both inside and out (rinse with RODI water and wipe it off with a towel) and you add in the you right amount of reagent. I’ve made these mistakes before with other checkers and gotten false results.

I gave it a nice wipe but I only rinsed the inside with RO, not cleaned with a cloth so I'll make sure to do that next time!

If these aren't done incorrectly how much do you reckon the readings could potentially be off?

 

[AydenLincoln]

Yeah that's what I was thinking! Especially as at the moment I'm trying to figure out how much to dose of all for reef.

Just tested again with the Hanna, made sure everything was nice and clean and it came out as 7.7, so tried the API again at 8.3

I will just keep trying until I perfect it, I guess!




I gave it a nice wipe but I only rinsed the inside with RO, not cleaned with a cloth so I'll make sure to do that next time!

If these aren't done incorrectly how much do you reckon the readings could potentially be off?

I can’t give you a specific number but in my experience A LOT.

 

[flyingscampi]

https://www.reef2reef.com/threads/hanna-alk-reagent.916562/

 

[Mr. Mojo Rising]

If you use 2 test kits, you will always get 2 different readings, the best is just choose one test kit and live and die by it. Corals care more about consistency than they do about a parameter adjustment of one or two points.

 

[DanTheReefer]

Both tests have an accuracy range, can be quite different results if they are on opposite edges.

Oh and yes you can screw up a Hannah test, one time I wasn’t paying attention and dumped the reagent into the colorimeter instead of the vial, oops.

Probably overdue a thread on Hannah hacks. For instance I like to store them upside down because the lids tend to push down on the button and kill the battery. Also things like how to cut reagent powder packs and clean / store vials

 

[TheSharksDen]

Make sure to calibrate it first. Cut the packets it came with and click calibrate button and stick it in the back of solution. Then once it calibrates rinse with clean water. Then it should be spot on.

 

[gbru316]

In my experience, it's easier to induce error with the Hanna than titration tests (API, salifert, etc).

Here was my hanna process, before I stopped using it:
1. Empty vial (I store them filled with RO/DI)
2. Shake hard to remove any remaining liquid
3. Add 10 mL sample, measured with autopipette
4. Attach cap, wipe for prints/grease
5. Prepare reagent sachet
6. Insert cuvette into checker such that writing is facing me, centered.
7. Take reference measurement (C1)
8. Remove cuvette only touching cap
9. Unscrew cap, making sure I only touch the highest portions of the cuvette glass (measurement devices in checker are about halfway down)
10. Add 1 mL reagent
12. Flip upside down/rightside up 5 times to mix (holding between thumb and forefinger)
13. Another prints/grease cuvette wipe
14. Insert cuvette into checker such that writing is facing me, centered.
15. Take measurement (C2)
16. Remove cuvette
17. Rinse cuvette and cap with RO
18. Rinse cuvette and cap with RO/DI
19. Fill with RO/DI
20. Store


Things that can impact measurement, if only very slightly:
1. fingerprints/grease on cuvette
2. reagent age
3. reagent batch
4. sample volume
5. Position of cuvette in checker (manufacturing tolerances in glass cuvette can lead to different sidewall thickness)
6. Improper/inaccurate reagent measurement
7. Battery state-of-charge
8. Ambient temperature
9. microbubbles
10. debris/detritus in sample

 

[NewbReef]

Sorry for the stupid question, but I'm not that experienced with syringes.

I'm unsure if I'm actually putting in the correct amount of reagent?

The syringe has a nozzle to attach and when I pull out the reagent, the nozzle itself is filled rather than the syringe so I can't get a visual aide.

If I pull the syringe all the way up so the bottom line is on 0.0ML, this will then give me exactly 1ML?

 

[ss30]

Yeah that's what I was thinking! Especially as at the moment I'm trying to figure out how much to dose of all for reef.

Just tested again with the Hanna, made sure everything was nice and clean and it came out as 7.7, so tried the API again at 8.3

I will just keep trying until I perfect it, I guess!




I gave it a nice wipe but I only rinsed the inside with RO, not cleaned with a cloth so I'll make sure to do that next time!

If these aren't done incorrectly how much do you reckon the readings could potentially be off?

With all for reef your better of dosing by the Calcium level rather then the dKH

 

[gbru316]

If I pull the syringe all the way up so the bottom line is on 0.0ML, this will then give me exactly 1ML?

Yes. The bottom of the plunger (opposite end of the part you out your finger on) should be on 0:0.

Syringe draw volume depends on the movement of the plunger. Tips don’t have any impact.

 

[omar jawad]

For consistency, I run the Hanna test at the same time every week. I use a scale to measure 10.3 grams of sample water. This way, I add a few more redundancies to help with consistent results.