Hanna alkalinity checker reagent off again

[CTaylor]

Hi,

This happens to each and every refill reagent I get. Over time the alkalinity reads too high. It will read correct for the first few weeks or so that I have it. Over time it drifts higher. It's the reagent, not the checker. I've used the old version of the reagent that had the film seal, and the new ones with the paper seal. I recall reading thread of inacurrate testers (due to reagent) in the past. It was thought that it was the interaction of the film seal or something along those lines with the fluid. Well, apparently that was not the issue.

The only reason I know the reagent is causing a high drift (on order of 1.5 dkH) is because I compared it to my salifert...and a brand new hanna reagent agreed 100% with the salifert.

Keeping the hanna reagent stored in fridge makes '0' difference.

Is hanna making another new batch? Do they even know about the issue? I doubt I'm the only one. Does anyone else know this is happening ? lol

From now on , though once every 2 weeks I'm using the Salifert as a test for the Hanna test. I thought the problem was solved with new packaging. I'm glad I thought to salifert test tonight!. I was at 6.2 dkH, when I thought I was at 7.7.

 

[Joe0813]

Mine seem to be alright. I'm going to keep an eye on it though

 

[CTaylor]

Mine seem to be alright. I'm going to keep an eye on it though

if it starts showing higher over time, you might suspect it... I have a back up Salifert that has always been on target

 

[ca1ore]

Mine reads almost 0.1 high. Hadn’t thought that it might be old reagent.

 

[CTaylor]

Mine reads almost 0.1 high. Hadn't thought that it might be old reagent.

It might be how long it's opened, not not how old it is (?). I dont know. But I know I go thorugh mine in a few months max. And every time toward the end (if not before) im' off 1.5 or more dkh

 

[ca1ore]

Sorry typo above - should have said that my Hanna reads 1.0 high.

 

[hkgar]

Just curious, what makes you sure that the Salifert is correct?

I notice a tendency (among most all testers) to believe the second test is the correct one

 

[CTaylor]

Just curious, what makes you sure that the Salifert is correct?

I notice a tendency (among most all testers) to believe the second test is the correct one

Easy : b/c I usually have a new hanna reagent on hand. Every time I go from current ("old") hanna reagent to new one I get a significantly lower reading on the new one. This is at least 3 times in a row. And the new one each time correponds almost exactly to what salifert has read every single time.

 

[CTaylor]

Until I have a reason to think otherwise, the salifert will be my standard and hanna will be the "quick check".

 

[hkgar]

Salifert makes excellent test kits for this hobby, but...
Each drop from the syringe is about .02 ml (.4 alk) and it is also dependent on what point you determine it has changed to red. Many more variables and chance for human error when using the Salifert kit for dKH.

I always use Salifert for Ca and Mag as small variances are of much less importance.

 

[CTaylor]

Salifert makes excellent test kits for this hobby, but...
Each drop from the syringe is about .02 ml (.4 alk) and it is also dependent on what point you determine it has changed to red. Many more variables and chance for human error when using the Salifert kit for dKH.

I always use Salifert for Ca and Mag as small variances are of much less importance.

No complaints about the salifert one. If I cant be sure about a reading, I just re-test it. And it usually confirms what it first seemed to be. it's always very close to what a fresh hanna batch reads.

 

[ROlympia]

I stopped using Hanna alk checker; I found it unreliable. I use only Salifert now.

 

[CTaylor]

I stopped using Hanna alk checker; I found it unreliable. I use only Salifert now.

i'm your side.. but I still use it for a quick check. and salifter for my every other "calibration"

 

[jrill]

I've never noticed this to happen.

 

[CTaylor]

I've never noticed this to happen.

have you compared to another test kit such as salifert? Or even just a new fresh hanna reagent right after using your used up one? You'll see....

 

[Joe0813]

I just checked mine... mine is still reading right

 

[CTaylor]

I just checked mine... mine is still reading right

how old is it?
perhaps it has to do with exposure to air??? so the more times it's opened the more times it has new O2 etc to expose to. I don't know.

 

[cjpitt80]

Interestingly, mine reads LOW after time. I'm usually in the 8dKH range and got a reading of 7.5. ALMOST dosed Bicarbonate, but decided to hold off. Tested 2 days later and it was 4.5. Freaked out. I mixed a batch of new water and tested 4.5!! Opened new bottle of reagent tested and 8.2....

 

[CTaylor]

Interestingly, mine reads LOW after time. I'm usually in the 8dKH range and got a reading of 7.5. ALMOST dosed Bicarbonate, but decided to hold off. Tested 2 days later and it was 4.5. Freaked out. I mixed a batch of new water and tested 4.5!! Opened new bottle of reagent tested and 8.2....

odd

 

[outssider]

I've been using the hanna alk checker since in came out. I buy 3 or 4 reagents at a time and put them in the fridge. I always check the last of one reagent with the beginning of the new one. The reagents are usually right on, if they're off it's only slightly. Even when they had the recall, my recalled reagents were ok....they stay in the fridge many many months maybe even a year before I get to the last bottle.....