Hanna Alkalinity Test Reagent Gone Bad?

[chiefifd]

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The Hanna Reagent isn't outdated 12/2024 but was probably opened 01/2024 (Best Guess).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.

 

[KrisReef]

Yes, these reagents can start to fail after opening &/or age.

The interesting thing I learned on here recently is that salt in a bucket can also drop off in Alk & Calcium as the salts react with moisture, i think ending up with calcium carbonate(? forgetting specific end product atm) that doesn't dissolve in water and impacts Alk, but does it lower it that much? I don't think so.

Hanna Reagents should likely be replaced. BumpS

 

[gbroadbridge]

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The Hanna Reagent isn't outdated 12/2024 but was probably opened 01/2024 (Best Guess).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.

This is very common.

The Hanna Alk reagent has a shelf life of 1-2 months after opening.
The best before/expiry date is only for unopened bottles.

Life can be extended to around 6 months if stored in the refrigerator.

 

[Dan_P]

This is very common.

The Hanna Alk reagent has a shelf life of 1-2 months after opening.
The best before/expiry date is only for unopened bottles.

Life can be extended to around 6 months if stored in the refrigerator.

I found the alkalinity reagent to be stable for at least eight months after opening

 

[Dan_P]

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.

Try a new reagent before raising the alkalinity

 

[gbroadbridge]

I found the alkalinity reagent to be stable for at least eight months after opening

Perhaps you should buy a lottery ticket

Seriously, I expect that local environmental conditions make a large difference to stability once opened.

 

[Dburr1014]

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 keep it in the fridge and it's been stable for a year.
Buy a new one and store it in the fridge.
Thanks to @Lasse for this one.

 

[chiefifd]

Thanks all, I've ordered new Hanna Alkalinity reagent, and a RED SEA Alkalinity kit to verify results.
The RED SEA salt had just been opened, I buy the 200 Gallon salt mix.
I'll test late this week and let everyone know my results.
Thanks for replying all

 

[Dburr1014]

Perhaps you should buy a lottery ticket

Seriously, I expect that local environmental conditions make a large difference to stability once opened.

Open and immediately close when doing test. Always refrigerate from new unopened to after each test. Swirl bottle before test to mix it up.

 

[Randy Holmes-Farley Verified Community Expert]

Perhaps you should buy a lottery ticket

Seriously, I expect that local environmental conditions make a large difference to stability once opened.

Yes, temperature and humidity are big factors in how fast organic molecules degrade.

In setting shelf stability standards, pharmaceuticals are placed in controlled chambers for fixed periods of time, with higher temps and humidity used to accelerate the process.

 

[Dan_P]

Perhaps you should buy a lottery ticket

Seriously, I expect that local environmental conditions make a large difference to stability once opened.

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.

 

[Dburr1014]

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.

Is this sample also refrigerated or left out? Curious.

 

[Lasse]

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

Do it give a stable reading when used as it should - to measure alkalinity? What I understand of your post - you have test if the reagent is stable - not of the measurements degrade with time. I have all my analysis chemicals in the refrigerator and there is no 1 dKH gap between an old (not hold in refrigerator) and a newly open anymore.

Sincerely Lasse

 

[Dan_P]

Is this sample also refrigerated or left out? Curious.

Room temperature.

 

[Dan_P]

Do it give a stable reading when used as it should - to measure alkalinity? What I understand of your post - you have test if the reagent is stable - not of the measurements degrade with time. I have all my analysis chemicals in the refrigerator and there is no 1 dKH gap between an old (not hold in refrigerator) and a newly open anymore.

Sincerely Lasse

If you stored the alkalinity reagent at room temperature, would the measured alkalinity be consistently low or consistently high compared to the new bottle?


I obtained the visible spectrum and acid content of the reagent as a way to characterize the reagent quality AND compared the alkalinity measured by the Hanna Checker with that measured by acid titration. Nothing that I measured changed over 8 months.

I am going to repeat this study with another bottle or maybe two bottles to confirm my results. I will run the study for one year this time.

 

[Randy Holmes-Farley Verified Community Expert]

If you stored the alkalinity reagent at room temperature, would the measured alkalinity be consistently low or consistently high compared to the new bottle?


I obtained the visible spectrum and acid content of the reagent as a way to characterize the reagent quality AND compared the alkalinity measured by the Hanna Checker with that measured by acid titration. Nothing that I measured changed over 8 months.

I am going to repeat this study with another bottle or maybe two bottles to confirm my results. I will run the study for one year this time.

Acid quantity won’t likely change, but oxidation of the dye may change the spectrum of absorbance vs pH

 

[chiefifd]

My Hanna Alkalinity reagent had been opened I'll say around January 2024 expiration date of 12/24.
The Reagent was opened and I probably did 3 or 4 tests with it all with normal readings around 7 dKH. The bottle was sealed back up placed in the checker plastic case until yesterday when I tested. I repeated the test with tank water twice and got the same reading 2.2 dKH. Then I repeated the test with a batch of Red Sea regular reef salt, same reading of 2.2 dKH. The Red Sea salt was just opened so it was "fresh".
I'm waiting on the new Reagents, the Hanna & a Red Sea Alkalinity test kit for verification.
My PH in the tank is monitored by my APEX and is a steady 7.95 to 8.03 so PH hasn't changed.
** I'll be refrigerating the Reagents from now on. My lax testing was due to a new Kitchen Cabinet build for my wife. Finally finished with that longgggg build.

 

[rtparty]

I routinely used expired Hanna alkalinity reagent with zero issues. Did this for years and never refrigerated it. Just shook before each use, cap off to get sample, cap back on tight, back into the Hanna storage box and into my cabinet.

I always opened a new bottle when my current bottle had a few tests left. Then I would cross reference them to each other. I never cared about the expiration date on them

 

[Dan_P]

Acid quantity won’t likely change, but oxidation of the dye may change the spectrum of absorbance vs pH

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?

 

[vetteguy53081]

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.

They can or may and best way to tell is to see if you can borrow a new pouch or buy One from LFS and see what result that packet produces