Hanna checks alkalinity in accurate

[Brandonsegula]

So I got the alkalinity checker and calcium checker. Calcium checked perfect. The alkalinity was way low and doubled checked myself using my salifert kit and sure enough the Hanna checker was testing low. How do I fix this?

 

[madweazl]

Hmm, my Hanna is never low compared to the other kits I have (Red Sea and Salifert); always a bit higher by about .25 dKH. There is no way to "fix" the Hanna kit but you can run a couple tests with both to see if the results are repeatable. I started using a syringe with the Hanna checkers to measure out the 10ml, I wipe down the bottles with a rag before I drop them in the checker, and I index the 10ml label on the cuvette the same direction (facing forward) so the bottle is aligned roughly the same each time I test. Outside of that, nothing you can do.

 

[Brandonsegula]

Hmm, my Hanna is never low compared to the other kits I have (Red Sea and Salifert); always a bit higher by about .25 dKH. There is no way to "fix" the Hanna kit but you can run a couple tests with both to see if the results are repeatable. I started using a syringe with the Hanna checkers to measure out the 10ml, I wipe down the bottles with a rag before I drop them in the checker, and I index the 10ml label on the cuvette the same direction (facing forward) so the bottle is aligned roughly the same each time I test. Outside of that, nothing you can do.

I did all that still reading way low. I emailed Hanna instruments to see if there is anything I can do differently.

 

[reefrf]

I'm gonna guess that the Hanna is correct but I would not act on any changes quite yet. You can purchase a calibration fluid that will tell you if it's working correctly. You're more than welcome to borrow mine to check. They cost $20 on line. My cell is 619-254-9320 if you want to come & check your tester.

 

[jpreefer]

You can reach out to Hanna on here, they have a very active rep on r2r

 

[Brandonsegula]

I'm gonna guess that the Hanna is correct but I would not act on any changes quite yet. You can purchase a calibration fluid that will tell you if it's working correctly. You're more than welcome to borrow mine to check. They cost $20 on line. My cell is 619-254-9320 if you want to come & check your tester.

I had my lfs actually test my water and they were getting the same reading as me. So I think the Hanna checker is off. Thank you I'll get back to you on that In a day or so. I email Hanna

 

[Brandonsegula]

I'm gonna guess that the Hanna is correct but I would not act on any changes quite yet. You can purchase a calibration fluid that will tell you if it's working correctly. You're more than welcome to borrow mine to check. They cost $20 on line. My cell is 619-254-9320 if you want to come & check your tester.

I had my lfs actually test my water and they were getting the same reading as me. So I think the Hanna checker is off. Thank you I'll get back to you on that In a day or so. I email Hanna

 

[Brandonsegula]

You can reach out to Hanna on here, they have a very active rep on r2r

I emailed their tech support

 

[Shameless_Dood]

I did all that still reading way low. I emailed Hanna instruments to see if there is anything I can do differently.

How much of a difference are we talking? Do you have the dkh version or the ppm version? Between your two tests they may be within their margin of error just reporting different numbers. Outside of what has already been recommended, I always check for bubbles on both cuvettes before I run the test. I have the PPM version and I typically run the test at least twice with the same samples. Sometimes I see a difference in each test, sometimes fairly large, sometimes small.

 

[Brandonsegula]

How much of a difference are we talking? Do you have the dkh version or the ppm version? Between your two tests they may be within their margin of error just reporting different numbers. Outside of what has already been recommended, I always check for bubbles on both cuvettes before I run the test. I have the PPM version and I typically run the test at least twice with the same samples. Sometimes I see a difference in each test, sometimes fairly large, sometimes small.

Salifert and Red Sea kits reading 9.5 Hanna is readin 7.8

 

[Reefltx]

Salifert and Red Sea kits reading 9.5 Hanna is readin 7.8

Wow, maybe the reagent is bad or old.
My Hanna is normally .2 higher than salifert.

 

[Brandonsegula]

Wow, maybe the reagent is bad or old.
My Hanna is normally .2 higher than salifert.

I contacted them so hopefully I'll know then what today. Until that I'll sit tight

 

[Shameless_Dood]

Salifert and Red Sea kits reading 9.5 Hanna is readin 7.8

Dang, yeah that's quite a difference. When does the reagent expire? That may be a clue. Or that particular device is just wonky.

 

[chefjpaul]

https://www.bulkreefsupply.com/hi75...rds-for-hi755-hanna-checker-marine-water.html

 

[Brandonsegula]

Dang, yeah that's quite a difference. When does the reagent expire? That may be a clue. Or that particular device is just wonky.

July 2018. I just don't know. I have the calcium one also. Used it and tested exactly what i tested on my Red Sea kit.

 

[jimk60]

I have the same problem. My checker was steady reading around 8.0 DKH. Bought new reagents exp 07 2018 lot 6522 and instantly had readings around 7.2. Ran the test between the old and new reagents and had the same result. I believe it's that reagent being that my red Sea read around 8.0

 

[Catfish2]

You may find this thread interesting. I had a similar issue.

https://www.reef2reef.com/threads/which-testing-kit-do-i-trust.319210/

 

[jimk60]

I'm about due for new reagent so it will be interesting to see my numbers then. Like everyone else I've just been shooting for consistency.

 

[BigJohnny]

My hanna is always within .1-.2 dkh of my salifert, sometimes in either direction. They both have small margins of error. You probably just have bad reagent or a scratched/dirty curvette.

 

[Black Pearl]

Same issue here, large difference between Salifert and Hanna. Salifert reads higher