Hanna Alkalinity Test Reagent Gone Bad?

[FernBluffReef]

Hearing about some folks tank temp issues / need for coolers, etc. I wonder if some comments are related to storage issues.

"Hanna Instruments recommends storing their reagents at room temperature, which is between +15°C and +25°C. The reagents should be kept in a tightly closed container in a dry, well-ventilated area, and protected from moisture and direct sunlight.". Fall outside of those parameters then the expiration date in the reagent is no longer valid persay

 

[Randy Holmes-Farley]

i have yet to induce the reagent to be unstable, so the visible spectrum of the dye in the acidic reagent remained the same over eight months. I did not check the dye spectrum at a more basic pH.

Before I start the next room temperature stability study, I’ll try accelerated aging at 100 C and separately look at solvent evaporation. Any other failure modes I should try? Pure oxygen in the head space?

Do you know the identity of the dye(s) ?

 

[Dan_P]

Do you know the identity of the dye(s) ?

No

 

[A_Blind_Reefer]

Funny how individuals can have totally different experiences. I believe those that state they’ve had zero issues. I can also personally attest to degradation once opened. Cap tightened properly (I mean, I didn’t break out a torque wrench or anything), tear open seal completely removed, under cap seal intact and in place (However, I do notice they are a bit small diameter wise and will fall out until they’ve been squished down a few times), stored in a dark cabinet in an air conditioned home (laundry room and low humidity), shook before each use and waited a bit so I wasn’t pulling in bubbles. Alk measurements would drift downwards after about two months. Nib unopened reagent stored in the same manner had zero issue, even if well expired. I always used fresh tips on the pipette (I have multiple and rinse and dry after each use). Bottles would only be opened long enough to pull the reagent and were closed immediately after. Once I started storing opened bottles in the fridge….no more issues. Is it oxygen, temp, humidity…I don’t know. I store all unopened bottles in the laundry room cabinet. I’ve had a nib bottle that was two years expired stored in the laundry room which was perfectly fine (against previous Hanna and checked against Salifert). Once opened….in the fridge it goes. I had drift issues for a couple years before I came across an @Lasse thread discussing the same and his experience with storing reagent in the fridge. Haven’t had a single issue since.

Current open bottle, stored in fridge, well expired and tests results are still inline.

 

[Dan_P]

Funny how individuals can have totally different experiences. I believe those that state they’ve had zero issues. I can also personally attest to degradation once opened. Cap tightened properly (I mean, I didn’t break out a torque wrench or anything), tear open seal completely removed, under cap seal intact and in place (However, I do notice they are a bit small diameter wise and will fall out until they’ve been squished down a few times), stored in a dark cabinet in an air conditioned home (laundry room and low humidity), shook before each use and waited a bit so I wasn’t pulling in bubbles. Alk measurements would drift downwards after about two months. Nib unopened reagent stored in the same manner had zero issue, even if well expired. I always used fresh tips on the pipette (I have multiple and rinse and dry after each use). Bottles would only be opened long enough to pull the reagent and were closed immediately after. Once I started storing opened bottles in the fridge….no more issues. Is it oxygen, temp, humidity…I don’t know. I store all unopened bottles in the laundry room cabinet. I’ve had a nib bottle that was two years expired stored in the laundry room which was perfectly fine (against previous Hanna and checked against Salifert). Once opened….in the fridge it goes. I had drift issues for a couple years before I came across an @Lasse thread discussing the same and his experience with storing reagent in the fridge. Haven’t had a single issue since.

Current open bottle, stored in fridge, well expired and tests results are still inline.

I love a good mystery. Sargent Friday would be very happy with your description of the event (…just the facts).

The drifting downwards fits a solvent loss hypothesis. I don’t think Hanna would use a volatile acid in the reagent formulation which would mean there won’t be an acid loss scenario with a corresponding alkalinity measurement rising with time. Still need to think through Randy’s idea of the dye molecule oxidizing and changing the color response of the reagent.

 

[A_Blind_Reefer]

I love a good mystery. Sargent Friday would be very happy with your description of the event (…just the facts).

The drifting downwards fits a solvent loss hypothesis. I don’t think Hanna would use a volatile acid in the reagent formulation which would mean there won’t be an acid loss scenario with a corresponding alkalinity measurement rising with time. Still need to think through Randy’s idea of the dye molecule oxidizing and changing the color response of the reagent.

Ha. Just the facts…

In previous discussions, people with the exact same lot/exp would have different experiences with one not having any changes in results while the other is. One hypothesis, for my issue, was that as I live in the ninth gate…Dante’s inferno…outside of Phoenix, Arizona, that maybe heat during shipping was a factor. Maybe, but why a two month lag after opening. Meaning that test results were inline for two months before degrading, That and I’ve purchased in fall/winter/spring when it’s fairly temperate and still had issues after a couple months. It almost seems hyper local and environment dependent as while some can repeatedly have issues, others can repeatedly not…even within the same lot (giving people the benefit of doubt that they aren’t leaving the bottle open, dipping a dirty or somehow contaminated syringe, shaking/mixing, strong in a dark cool place, etc.). I understand issues arising when someone leaves their open reagent on top of some metal halides for two months, in a humid sump cabinet, wherever. I have faith that at least some participating in previous discussions had a grip on proper storage and use….but you never know…Look forward to more of your thoughts and findings.

 

[Dan_P]

Ha. Just the facts…

In previous discussions, people with the exact same lot/exp would have different experiences with one not having any changes in results while the other is. One hypothesis, for my issue, was that as I live in the ninth gate…Dante’s inferno…outside of Phoenix, Arizona, that maybe heat during shipping was a factor. Maybe, but why a two month lag after opening. Meaning that test results were inline for two months before degrading, That and I’ve purchased in fall/winter/spring when it’s fairly temperate and still had issues after a couple months. It almost seems hyper local and environment dependent as while some can repeatedly have issues, others can repeatedly not…even within the same lot (giving people the benefit of doubt that they aren’t leaving the bottle open, dipping a dirty or somehow contaminated syringe, shaking/mixing, strong in a dark cool place, etc.). I understand issues arising when someone leaves their open reagent on top of some metal halides for two months, in a humid sump cabinet, wherever. I have faith that at least some participating in previous discussions had a grip on proper storage and use….but you never know…Look forward to more of your thoughts and findings.

Are you close to Roswell? You never know

 

[A_Blind_Reefer]

Are you close to Roswell? You never know

 

[Reefer Matt]

If I get a reading that is off, I’ll test again to make sure. With the Hanna alk reagent, I swirl the bottle for a few seconds before use, being careful not to introduce a lot of air. I can use a whole bottle down to the last drop without issue. My opinion is that the reagent doesn’t stay homogenized, and that’s why some people have issues.

 

[reefer2/19/24]

I've had a busy summer like everyone, haven't tested my 90 gallon reef I've had set up for about 10 years in several months.
I use Hanna Checkers for most of the water parameters. This morning I tested for Alkalinity and got a reading of 2.2 dKH with the Hanna Checker. I re-tested and got the same approximate reading of 2.1 dKH. I've been using RED SEA regular salt for several years, so I mixed up a new batch of salt, tested it, I was shocked to see 2.2 dKH from the fresh batch of RED SEA salt mix.
The Hanna Reagent isn't outdated 12/2024 but was probably opened 01/2024 (Best Guess).
I hadn't checked for Magnesium in the tank which could be an issue. But the new batch of water using RE SEA salt should be around 7 dKH. The PH in the tank is 8.02 - Calcium 450 - Nitrates 9.5
Looks like my Reagent went bad I'm thinking, wondering if anyone else experienced a like event.

I got some alk regent and it wasn't expired but had a lot of floaters (picture orange juice pulp) contacted Hanna and they sent a new regent replacement for Free! Never hurts to ask!

 

[chiefifd]

I've sent away for a new bottle of Hanna Alkalinity Reagent & a Red Sea Alkalinity test kit for verification of the results.
When I get the order in the mail later this week I'll put up the results here.

 

[Dan_P]

If I get a reading that is off, I’ll test again to make sure. With the Hanna alk reagent, I swirl the bottle for a few seconds before use, being careful not to introduce a lot of air. I can use a whole bottle down to the last drop without issue. My opinion is that the reagent doesn’t stay homogenized, and that’s why some people have issues.

It seems to be a clear solution. I will look more carefully at the next bottle’s contents.

 

[A_Blind_Reefer]

I’m also curious as to how similar/dissimilar other reagents are in composition (ie auto testers). I don’t have to gently swirl or shake my trident three times a day. I don’t have to put it in the fridge either. Of course the reagent needs to be refilled every two months….hmmm….right about the same timeframe that my Hanna starts to drift. Wonder if that’s by design or pure coincidence. I don’t hear those mixing gallons of abc complaining about drift though, or having to stir or refrigerate.

 

[HomebroodExotics]

I stopped using Hanna for alk over a year ago after figuring out it was dropping quite significantly on my readings. My reagents were never older than a few months and i didn’t keep them in the fridge. I also noticed that it gets some snot in the bottle that occurs at the same time that testing starts to go down. Anyway it was a lot of money for bad accuracy so I just use sera drops to check alk now. Way better.

 

[Lasse]

It almost seems hyper local and environment dependent as while some can repeatedly have issues, others can repeatedly not…even within the same lot

And I live at 57.78° N , although the climate is better than Kodiak Island - its the opposite to the heat inferno of Arizona . And now - that explanation disappeared up in the blue

I did some tests during a year or so before I post my findings. The only way I could trust the reagent after around 1.5 months use was when it was stored in the refrigerator. I tested all the other mentioned tricks. For me - its not a brainer - its rather normal that chemical used in analytical works is stored in a refrigerator.

Sincerely Lasse

 

[TangerineSpeedo]

It happens. My friend who owns an Aquaculture company asked me the other day if I had any extra reagent because he was getting some low 2's. Sure enough with fresh reagent, he got a much more reasonable reading.

 

[Reef Puncher]

I’ll buy a ticket as soon as I am done typing

By the way, is the bad reagent giving low alkalinity readings?

I just finished an eight month stability study on a newly open reagent bottle. Nothing changed over this time. I opened the bottle every ten days for a minute to simulate grabbing a sample and every thirty days I grabbed a 3 mL sample for analysis. The reagent is stable.

My thinking right now about the reagent degradation is that the caps are not being adequately tightened, the white cap liner is missing, and/or the safety seal is only partially removed from the rim. I am going to look deeper into this stability observation.

i use the hannah for all my testing, but i also have backup aquaforest test kits. if ever i get a wierd reading, i compare it to the aqua to be sure. i highly recomend buying some aquaforest backup test kits for alk and more

 

[chiefifd]

Well I got the new Hanna Alkalinity reagent today. I tested the tank water, with the new Hanna reagent it measured 7.5 (Old Alkalinity reagent measured 2.2) . New batch of Red Sea saltwater with the new Hanna reagent it measured 8.9 (Old Alkalinity reagent measured 2.2) .

Sure looks like the old but not outdated Hanna Alkalinity reagent was definitely bad.

This weekend I'll check Alkalinity with the Red Sea Alkalinity checker to verify accuracy. Thanks everyone for looking.