Hannah Alkalinity Refill inaccurate.

[Randy Holmes-Farley Verified Community Expert]

Can any moderators watching move this to the Hanna forum?

For many reasons, I would start a new thread there, rather than suggesting we move it.

 

[Randy Holmes-Farley Verified Community Expert]

Thats why the alk calibration/confirmation sample is critical. VERY well worth the $20!!!

I would probably contact Hanna first with the batch information if I had a bad reagent, thats not BRS's fault.

https://www.bulkreefsupply.com/hi772-11-alkalinity-dkh-calibration-check-set.html

I agree it can be useful, but a true alk standard would be far more useful (IMO).

You likely know this, but just to be clear, that Hanna standard only evaluates the testing device, and will not indicate problems that may arises due to bad reagents, bad methodology (timing, etc.), a scratched cuvette, or a real change in the tank alkalinity.

 

[Randy Holmes-Farley Verified Community Expert]

Folks concerned about reproducibility should also note that the Hanna alk checker only claims to read accurately within a range of +/- 0.3 dKH, so two readings can be 0.6 dKH apart and be perfectly in line with Hanna's accuracy expectations.

 

[Randy Holmes-Farley Verified Community Expert]

;Wideyed that's way to much

It's the claim on their web site (+/- 0.3 dKH or +/- 5%). Folks often have unrealistic accuracy expectations for electronic devices.

 

[Randy Holmes-Farley Verified Community Expert]

Just to play devil's advocate, and because I can't Google it at the moment. Does salifert publish an accuracy spec? How does it compare?

No.

 

[Wilsonfeliz]

I also saw stuff floating in the alkalinity reagent that I am currently using, and although I have not noticed reading errors, it was strange to me.

Maybe we should contact Hanna's service.

Tonight I can give you the lot number, I bought mine at Marine Depot a few months ago.

Lot: 7390

 

[Potatohead]

I have three lots here, 7499, 7523 and 7573. I opened a new 7573 last night and it reads identical to the older 7499 I have been using for a month or so. I don’t have a 7390 on hand but I’m sure I had one at some point because I use a bottle every 5-6 weeks. I don’t know.

 

[WWIII]

Thanks for coming in on your weekends to continue your great advice and help @Randy Holmes-Farley !

 

[Bayareareefer18]

DivingTheWorld, I agree with you. I am very through with my testing procedures. And all I heard Hanna saying is their detectors are accurate. Their statements do not address the consistency of the Reagent.

I have many thousands of dollars invested in Corals and fish. Hannah checkers being 1 DKH off, as many people have stated in this thread, is not acceptable.

I am going to have to go back to the Salifert.

I agree here. From all these posts it seems many are experiencing consistent inaccurate readings and not inconsistencies due to testing methods. I am a fan of hannah but just to state its the testing methods without looking into this any further seems dismissive.

 

[Art2249]

After reading this thread today I decided to check my reagent. I just bought a new one and figured out I had been using the wrong reagent. My checker is HI772. I had been using reagent HI755-26 which works with the HI755 checker. The thing is both reagents read the same. I tested 2 tanks each with both reagents followed by a salifert test. Here are the results:
tank 1
HI772-26 reagent=7.9
HI755-26 reagent=7.9
salifert=7.7
tank 2
hi772-26 reagent=7.9
HI755-26 reagent=7.7
salifert=7.9

 

[Potatohead]

After reading this thread today I decided to check my reagent. I just bought a new one and figured out I had been using the wrong reagent. My checker is HI772. I had been using reagent HI755-26 which works with the HI755 checker. The thing is both reagents read the same. I tested 2 tanks each with both reagents followed by a salifert test. Here are the results:
tank 1
HI772-26 reagent=7.9
HI755-26 reagent=7.9
salifert=7.7
tank 2
hi772-26 reagent=7.9
HI755-26 reagent=7.7
salifert=7.9

The reagents are the same. The only difference is one checker calculates dkh and the other ppm, but they both work exactly the same way, just the end calculation and display differs.

 

[Randy Holmes-Farley Verified Community Expert]

Thanks for coming in on your weekends to continue your great advice and help @Randy Holmes-Farley !

Thanks.

 

[Danj]

Folks concerned about reproducibility should also note that the Hanna alk checker only claims to read accurately within a range of +/- 0.3 dKH, so two readings can be 0.6 dKH apart and be perfectly in line with Hanna's accuracy expectations.

To add to this, I don't own the Salifert kit, but I do own the Red Sea kit which is also titration-based. I've noticed that a single drop from the titrator syringe tip is about .04 ml, which equates to ~0.6 dKH. So loosely speaking that means your readings will have approximately the same error in precision as the Hanna's, +- 0.3 dKH. My gut tells me Salifert would be the same, but I don't really know enough about that kit to speculate with any confidence there. Anyway, maybe it's because I have an inherent mistrust in subjectivety, but all things being equal I'd go digital every time.

 

[cracker]

Speaking of scratched vials . I was having issues & my vials were old & etched .I ordered new ones & automagically the issues disappeared

 

[Brew12]

Alkalinity testing is driving me nuts right now. I have 3 ways to measure and all 3 are consistent and repeatable.
Salifert: 8.6dkh
Redsea: 7.3dkh
KH Director: 7.6dkh

I'm guessing the KH Director is closest. BTW.. this was checked with 2 different Salifert test kits, 1 Redsea kit, and a before and after full calibration of the KH Director.
I also came across this.
https://www.advancedaquarist.com/2007/8/review
Where Dana Riddle did some testing and found the Salifert test was consistently 11% high and the Redsea was 19% low. This is an older test and may have changed since then.

Here is a more recent one that show Salifert much higher and Redsea to be a little lower.
https://www.advancedaquarist.com/2012/6/chemistry

Alkalinity testing is about clear as mud.

 

[Terry Brown]

In reviewing the graph below, the sharp dip in alkalinity 9.6 to 8.1 was when I started using the new Hannah Reagent (The Salifert read 9.1). I continue to test at about 8.1 with two different bottles of the new reagent. The Salifert now tests about 0.6 dKH higher. What I am noticing now in the graph was a slow increase in alkalinity before i used up the old bottle of reagent. I am wondering now if the reagent is going bad as the bottle was getting emptied. At the time I just thought the coral where using less, so I adjusted my doser from 10 ml to 9 ml daily. Funny thing is the alk. continued to creep upwards.

My complaint is not the 8.1 or 9.6 readings. My issue is the consistency of the reagents between lot numbers on the bottle. But now I am wondering if the old reagent was going bad as I was using it. I go thru a bottle a month, so it should not be going bad that quickly.

 

[madweazl]

Just ran two tests this morning.

Lot 7415 is the old reagent; after performing this test, there isn't enough reagent left to perform another so the bottle is essentially empty now.

Alk 120

Lot 7664 was just opened this morning.

Alk 120

I didn't expect the readings to be exact but they're usually close as previously mentioned.

I guess I'll describe the procedure I use for giggles:

Rinse 5ml syringe with tank water
Fill cuvette with 10ml of water from above syringe
Cap cuvette and wipe it down with a clean towel
Run first step in checker
Add reagent with included syringe and tip and wipe cuvette down with towel again
Take reading in checker
Rinse cuvette with tap water and dry it out with paper towel
Rinse reagent syringe tip with tap water (air dries in test kit box)

When opening new reagent bottles, I used a razor to cut out the plastic cover leaving the portion glued to the top of the bottle to act as a gasket of sorts. This seemed to help prevent any reagent from leaking out on past bottles. This latest reagent had a new style seal that has a pull tab (hopefully it seals up well).

 

[Bayareareefer18]

Just received my alk refill and a salifert kit as well. Wow is the salifert so much easier to read than the red sea

Salifert read 8.5
Hannah read 8.2

 

[cracker]

We can't go down that rabbit hole of which is the mast accurate. You will get lost .

 

[tsav87]

Finally got around to checking red sea pro vs hanna.

Rsp 8.7 dKh
Hanna 8.6 dKh (Lot # 7522)

Yeh, gonna keep using hanna. Easy to read and apparently still accurate.