Does Hanna alk reagent need to be refrigerated?

[shadyraro]

I agree. I started doing this and readings have been rock solid for 3 vials. Before they would get unreliable near the end of the vial. I even used one vial for months keeping in fridge and it was spot on compared to a new vial on the last test.

Im sold on keeping them in the fridge.

How do you know your readings are correct and what are you comparing them with? I started refrigerating my reagant after seeing a post here a couple months ago but I'm not convinced this is correct. If the manufacturer doesn't say to refrigerate it then why would you?
I compared my hanna to salifert yesterday and the readings were way out being Hanna 8.4 and salifert 9.9.
Neither tests are expired and I tested 3 times, so what does one do...

 

[billyocean]

How do you know your readings are correct and what are you comparing them with? I started refrigerating my reagant after seeing a post here a couple months ago but I'm not convinced this is correct. If the manufacturer doesn't say to refrigerate it then why would you?
I compared my hanna to salifert yesterday and the readings were way out being Hanna 8.4 and salifert 9.9.
Neither tests are expired and I tested 3 times, so what does one do...

The argument isn't if the hanna is the most accurate tester. The argument is that the reagent will read different after a while if unrefrigerated. And it's not really an argument if it changes over time unrefrigerated because yes....it does.

 

[Reefahholic]

Mine has been in room temperature, and I’m getting very accurate readings.

 

[billyocean]

Without typing a bunch of info..consistency changes after a couple of weeks ish versus refrigerated.

 

[shadyraro]

The argument isn't if the hanna is the most accurate tester. The argument is that the reagent will read different after a while if unrefrigerated. And it's not really an argument if it changes over time unrefrigerated because yes....it does.

Where does it say it’ll be different if reagant is unrefrigerated? If it is supposed to be refrigerated the manufacturer would’ve clearer stated to do so.

 

[Randy Holmes-Farley Verified Community Expert]

How do you know your readings are correct and what are you comparing them with? I started refrigerating my reagant after seeing a post here a couple months ago but I'm not convinced this is correct. If the manufacturer doesn't say to refrigerate it then why would you?
I compared my hanna to salifert yesterday and the readings were way out being Hanna 8.4 and salifert 9.9.
Neither tests are expired and I tested 3 times, so what does one do...

Reefers have determined all sorts of problems with manufacturer claims. I don’t know if refrigeration is useful, but the fact that Hanna doesn’t mention it carries no weight to me. They might even know it is helpful, but fear reduced sales.

 

[billyocean]

Where does it say it’ll be different if reagant is unrefrigerated? If it is supposed to be refrigerated the manufacturer would’ve clearer stated to do so.

It's not a debate. Do what makes you feel good. I've given my advice.

 

[exnisstech]

Refrigerate..not even up for debate. Shake before using, don't leave it open long, Refrigerate. Numbers will stay on point if you follow that and it keeps accuracy

Been doing this for over a year with very consistent test results. I'm more concerned with consistency than accuracy. The corals will tell me if accuracy is way off.
Shaking before use is a given at least to me. I shake every liquid except carbonated beverages. I only shake those when I'm getting one for someone I'm not fond of.

 

[Reefahholic]

I have to invert the reagent bottle a few times before each test, or I get inconsistent readings at the bottom of the bottle.

 

[hart24601]

How do you know your readings are correct and what are you comparing them with? I started refrigerating my reagant after seeing a post here a couple months ago but I'm not convinced this is correct. If the manufacturer doesn't say to refrigerate it then why would you?
I compared my hanna to salifert yesterday and the readings were way out being Hanna 8.4 and salifert 9.9.
Neither tests are expired and I tested 3 times, so what does one do...

I used a new vial (just opened) and old (fridge) to compare and also used salifert test which normally aligns well with my Hanna if the vial is new or refrigerated.

I’m surprised you see that much difference between the companies.

Before my old Hanna vials varied from salifert drastically. I also used an alkatronic and later a trident to compare with.

No clue why Hanna doesn’t say keep cold, odd to me as well if it helps.

Also my old room temp Hanna vials would eventually clump over time. In fridge they have not, not yet at least.

Just my experience but I have compared quite a bit and with other tests and devices. I actually had stopped using Hanna due to end of vial issues until Lasse said to refrigerate so I put it though the paces.

 

[Reefer Matt Verified Media Partner]

I am curious now!
I have never refrigerated it. But I do have an "old" bottle down to it's last 1-2 ml, and a brand new one. I think a video is in order to see.

 

[Reefer Matt Verified Media Partner]

I just did a test for my alk checker (HI772). In this one instance, the "old" reagent read 8.1 dkh twice. The brand new bottle, 8.0 dkh twice. I performed four tests total. Same cuvette used on all tests.

My Apex Trident says 8.16 dkh as well.
I swirl the reagent bottle to ensure it is mixed up with little to no air bubbles.
I'm not saying refrigeration doesn't work, but I am saying that what I do works for my situation as well.

 

[billyocean]

I just did a test for my alk checker (HI772). In this one instance, the "old" reagent read 8.1 dkh twice. The brand new bottle, 8.0 dkh twice. I performed four tests total. Same cuvette used on all tests.

My Apex Trident says 8.16 dkh as well.
I swirl the reagent bottle to ensure it is mixed up with little to no air bubbles.
I'm not saying refrigeration doesn't work, but I am saying that what I do works for my situation as well.

Nice..the point is it doesn't hurt to refrigerate and it can alter the reagent if unrefrigerated

 

[hart24601]

Age of the reagent no doubt is a variable that could potentially impact drift as well. I wouldn’t expect to see much drift stored at room temp if someone uses it frequently.

 

[Lasse]

The original thread is here https://www.reef2reef.com/threads/i...-for-hanna-marine-alkalinity-checkers.893762/.

I only want to add that sometimes you get a white precipitate in the sample and the readings get higher than they should. This seems not to be coupled to refrigerator or room temperature but into an use of not enough clean pipes.

Each one decide by themselves how to store the reagent but I personally always store it in the refrigerator

In my case - stored in room temperature > 5 weeks get too low reading. Compared with a newly opened reagent bottle

Sincerely Lasse

 

[shadyraro]

It's not a debate. Do what makes you feel good. I've given my advice.

I'm just saying that hanna states for accurate testing results the sample water needs to be @25C, and my fridge is 3C.

 

[Lasse]

I´m just saying - in my case I do the math - 10 ml at 25 degree C saltwater has a mass of 10 * 1.0237 = 10.237 gr and the Hanna alk reagent has a density of 1.01 at the same temperature. (SDS) If only take the waters density at 4 degree C in consideration - the density of the Hanna reagent should be around 1.012 at 4 degree C. This give us the equation (between the index finger and the thumb) (25*10.237 + 4*1.012) / 11 -> 23.71 degree C in the final sample. Checks with a lot of other methods has shown me that this difference in sample temp do not play a major role for the result

Further on - If my water has been at the temperature of 26.5 degree C - my density of it should be around 1.0235 which give the equation of (26.5*1.0235 + 4*1.012)/11 -> 25,02 degree C - fulfilling the spec of Hanna

What I am not saying is that everyone should apply this method. If it works for you to store your reagent in ambient temperature - stay with that. I did not work for me - but with the refrigeration method - I can use at least my reagents for a prolonged time and with fewer dip into the lower ends of its accuracy - being sure that the result is as good as it could be.

May also note that the accuracy for the dKH variant is ±0.3 dKH ±5% of reading @ 25 degree C and this is the only time 25 degree C is mentioned in the manual

here and here

Sincerely Lasse

 

[dennislagoon]

To me, I like testing alk to be quick, simple and accurate enough.

I had 2 major swings in the first year of the hobby until I figured out the Hanna reagent could go bad after a while. I just can never really trust it again after a couple of uses, refrigerated or not, unless I double check it with a new reagent or a Salifert test.

Which totally beats the point of being quick, simple and somewhat accurate. So went back to Salifert which is less worrisome and even cheaper.

 

[Hooz]

Once opening, I keep mine in the fridge and shake before each use. I open it, draw the needed amount out of the bottle, then close it back up and put it back in the fridge before proceeding with my test.

I've done several comparisons over the last few years and determined (in MY experience) the reagent lasts almost indefinitely that way. Certainly longer than it's taken me to get through a bottle anyway.

 

[Doctorgori]

Yeah when I 1st saw the @Lasse fridge thing it made no sense to me either, but since I was getting wack end of bottle readings I’ve since refrigerated and I’ve had no issue since….never bothered to do a “control” ….
FWIW could be a placebo effect, who knows