Problem with Hanna alk reagent

[exnisstech]

Hello all. I've been trying to keep a closer eye on my alkalinity lately. I'm using a hanna dkH checker. Last night I finished a bottle of reagent and had a reading of 8.6. today I come home and test with a new bottle and my reading is 9.8. I'm like what the heck. I'm not dosing so why did it go up. So I open another box and test and its 12.7. Now I'm really confused not to mention a little upset because at this point I have no clue what my readings really are. The checker has been the only thing I have been using and now I'm wondering was the first bottle accurate, the second or the third? Does anyone have any idea how I should proceed from here to get an accurate reading? Is there another method for testing alk that would be recommended to try and get this figured out? I seem to loose quite a few corals now and then for no reason and in this tank I can not even grow zoas or green star polyp, mushrooms or ricordia along with other "easy to grow" corals that other folks can't seem to get rid of and now I'm wondering if it has been because of bogus alk readings. I've been using Hanna checkers for alk and PH for over a year and now I'm really confused on how to proceed. I only have a few LPS and a couple of leathers in this tank. I have quite a few nice LPS and a few SPS srags in another tank that are doing good but now I'm afraid to even test that one.

 

[Nanojoe]

BRS has hanna calibration kit you can use to see if your checker is out of calibration.

You are certainly not the first to run into this same issue. There are some other threads on here that go through this...

 

[Pistondog]

Hello all. I've been trying to keep a closer eye on my alkalinity lately. I'm using a hanna dkH checker. Last night I finished a bottle of reagent and had a reading of 8.6. today I come home and test with a new bottle and my reading is 9.8. I'm like what the heck. I'm not dosing so why did it go up. So I open another box and test and its 12.7. Now I'm really confused not to mention a little upset because at this point I have no clue what my readings really are. The checker has been the only thing I have been using and now I'm wondering was the first bottle accurate, the second or the third? Does anyone have any idea how I should proceed from here to get an accurate reading? Is there another method for testing alk that would be recommended to try and get this figured out? I seem to loose quite a few corals now and then for no reason and in this tank I can not even grow zoas or green star polyp, mushrooms or ricordia along with other "easy to grow" corals that other folks can't seem to get rid of and now I'm wondering if it has been because of bogus alk readings. I've been using Hanna checkers for alk and PH for over a year and now I'm really confused on how to proceed. I only have a few LPS and a couple of leathers in this tank. I have quite a few nice LPS and a few SPS srags in another tank that are doing good but now I'm afraid to even test that one.

I have a red sea alk checker for this reason. Only accurate to 0.5 dkh, but that's all I need for a sanity check.

 

[Woodyman]

Hello all. I've been trying to keep a closer eye on my alkalinity lately. I'm using a hanna dkH checker. Last night I finished a bottle of reagent and had a reading of 8.6. today I come home and test with a new bottle and my reading is 9.8. I'm like what the heck. I'm not dosing so why did it go up. So I open another box and test and its 12.7. Now I'm really confused not to mention a little upset because at this point I have no clue what my readings really are. The checker has been the only thing I have been using and now I'm wondering was the first bottle accurate, the second or the third? Does anyone have any idea how I should proceed from here to get an accurate reading? Is there another method for testing alk that would be recommended to try and get this figured out? I seem to loose quite a few corals now and then for no reason and in this tank I can not even grow zoas or green star polyp, mushrooms or ricordia along with other "easy to grow" corals that other folks can't seem to get rid of and now I'm wondering if it has been because of bogus alk readings. I've been using Hanna checkers for alk and PH for over a year and now I'm really confused on how to proceed. I only have a few LPS and a couple of leathers in this tank. I have quite a few nice LPS and a few SPS srags in another tank that are doing good but now I'm afraid to even test that one.

I keep a Salifert alk test kit on hand for this reason. I check periodically and especially with each new bottle. I threw away a bottle once when it kept reading 4 points lower then the previous bottle, this was after verification with the Salifert.

 

[exnisstech]

Thanks for the responses. I found a Salifert kit I had hidden away that wasn't expired. It tested 11.5. So its closer to the last reading of the hanna. I'm thinking I may be better just going back to traditional test kits and just keeping two different brands for comparison (or 3 and going with the best 2 out of 3 ?). The hanna tester is so convenient but if the reagents are crap its pretty much useless IMO. Three bottles and three substantially different readings, really? What really sucks is I used baking soda to raise the alk a few weeks ago and it appears it wasn't even low to begin with. Its a continuous learning experience I guess. check your checkers lol

 

[Rmckoy]

I’ve been testing mine every other day and for the last few weeks every test is higher .
not dosing anything and wondering what’s being added while I’m at work .
my wife is adamant she hasn’t added and doesn’t add anything …

so that being said I pulled out the salifert kit and to my surprise a huge difference , alk numbers are at 7.3
My goal is 7.5dkh .

 

[ReeferSamster]

Last night I finished a bottle of reagent and had a reading of 8.6.
today I come home and test with a new bottle and my reading is 9.8. So I open another box and test and its 12.7.

That is strange. If the checker is out of calibration, shouldnt it just show an incorrect reading but still keep the same reading? Does being out of calibration also make the checker jump around?

Are you sure you wiped the bottle clean from your fingerprints and also get the water level EXACTLY on the bottle line with the curved miniscus of the water? I use a pipette with mL readings to fill the bottle with sample water to get the exact same amount every time. I wouldn't rely on eyeballing the water line.

 

[FishyFishFish]

Most of these errors are due to contamination of the bottle or the reagent. I’m not saying that there can’t be differences in the reagents but there are so many things that can affect the test that it’s often not the reagent that is at fault.

Here’s how I have got more consistent results.

1) Always flush the vials out with RODI water after use and store them full of RODI.

2) Clean the vials thoroughly before the initialization and before the test.

3) Always use a single vial (not one for the initialization and a different one for the test) and make sure it is always put in the checker the same way round (I put the 10ml mark facing me).

4) Keep the reagent bottle closed as much as you can.

5) Count the number of tests (I mark them on the bottle). The bottle is good for 25 tests but there is more than 25ml fluid in there. Once I’ve done the 25, I throw the bottle away.

6) Possibly a controversial one, but I never clean the syringe and I don’t let the tip touch anything. I couldn’t guarantee that it was completely dry after cleaning, and think this may have been affecting my results.

7) It has been reported that some of the 10ml lines on the vials are not accurate. I haven’t had this problem but, if you are getting inaccurate results, it might be worth measuring the sample water with a syringe.

8) Make sure the battery is not flat.

If you’ve done all of this and there are still big errors, then I would start question either the reagent or the colorimeter.

 

[exnisstech]

That is strange. If the checker is out of calibration, shouldnt it just show an incorrect reading but still keep the same reading? Does being out of calibration also make the checker jump around?

Are you sure you wiped the bottle clean from your fingerprints and also get the water level EXACTLY on the bottle line with the curved miniscus of the water? I use a pipette with mL readings to fill the bottle with sample water to get the exact same amount every time. I wouldn't rely on eyeballing the water line.

I don't think its a calibration issue or the readings would be more consistent rather than changing with each bottle of reagent. My guess is a problem with the reagent since the reading are so different from 3 different bottles. I'm pretty good about cleaning the cuvette after step one and then again after step 2 and making sure its just at the line so if its off it isn't by more than a drip or 2 out of a syringe. I fill a drip at a time when its close and I view it from the same angle when filling so all tests should be pretty consistent on water volume.

 

[mdb_talon]

That is not uncommon. Multiple people here have had the issue with different bottles giving wildly different results including myself.

And ya it is not a calibration issue it is an issue with the regeants. I tossed my hanna alk checker in the trash for this reason. Salifert works great for me.

 

[moz71]

It’s the reagent. Convinced. I changed bottles and have big differences. I see clumps coming out of some bottles. 2 times water turned yellow.

 

[moz71]

That is not uncommon. Multiple people here have had the issue with different bottles giving wildly different results including myself.

And ya it is not a calibration issue it is an issue with the regeants. I tossed my hanna alk checker in the trash for this reason. Salifert works great for me.

Hey posted almost same thing at same time. Lol. Only difference I am still riding out the checker. Lol

 

[mdb_talon]

Most of these errors are due to contamination of the bottle or the reagent. I’m not saying that there can’t be differences in the reagents but there are so many things that can affect the test that it’s often not the reagent that is at fault.

Here’s how I have got more consistent results.

1) Always flush the vials out with RODI water after use and store them full of RODI.

2) Clean the vials thoroughly before the initialization and before the test.

3) Always use a single vial (not one for the initialization and a different one for the test) and make sure it is always put in the checker the same way round (I put the 10ml mark facing me).

4) Keep the reagent bottle closed as much as you can.

5) Count the number of tests (I mark them on the bottle). The bottle is good for 25 tests but there is more than 25ml fluid in there. Once I’ve done the 25, I throw the bottle away.

6) Possibly a controversial one, but I never clean the syringe and I don’t let the tip touch anything. I couldn’t guarantee that it was completely dry after cleaning, and think this may have been affecting my results.

7) It has been reported that some of the 10ml lines on the vials are not accurate. I haven’t had this problem but, if you are getting inaccurate results, it might be worth measuring the sample water with a syringe.

8) Make sure the battery is not flat.

If you’ve done all of this and there are still big errors, then I would start question either the reagent or the colorimeter.

The thing is for many of that have had this issue we can get consistent results repeatedly with one bottle of regeant....then with another bottle get very different(yet consistent with that bottle) results. It points yo an issue with the regeants

 

[exnisstech]

Most of these errors are due to contamination of the bottle or the reagent. I’m not saying that there can’t be differences in the reagents but there are so many things that can affect the test that it’s often not the reagent that is at fault.

Here’s how I have got more consistent results.

1) Always flush the vials out with RODI water after use and store them full of RODI.

2) Clean the vials thoroughly before the initialization and before the test.

3) Always use a single vial (not one for the initialization and a different one for the test) and make sure it is always put in the checker the same way round (I put the 10ml mark facing me).

4) Keep the reagent bottle closed as much as you can.

5) Count the number of test (I mark them on the bottle). The bottle is good for 25 tests but there is more than 25ml fluid in there. Once I’ve done the 25, I throw the bottle away.

6) Possibly a controversial one, but I never clean the syringe and I don’t let the top touch anything. I couldn’t guarantee that it was completely dry after cleaning, and think this may have been affecting my results.

7) It has been reported that some of the 10ml lines on the vials are not accurate. I haven’t had this problem but, if you are getting inaccurate results, it might be worth measuring the sample water with a syringe.

8) Make sure the battery is not flat.

If you’ve done all of this and there are still big errors, then I would start question either the reagent or the colorimeter.

I flush with rodi but do not store them full.
clean before each test.
same vial used for the entire test.
bottle is closed after extracting 1 ml for testing. Only need to spill one on the counter once to learn that ;-)
I do flush the syringe with rodi after use.

I'm leaning toward the reagent as I am doing everything exactly the same as I have for months and if I hadn't run out of reagent I would be a happy camper and not trying to figure out the problem as my readings would still be consistent. At this point I'm just trying to figure out the best way to get accurate consistent readings so I don't go chasing numbers that are not even accurate. I think a more traditional test kit or two is probably the best way to go. Tech is tech, its great when it works but not so much when it doesn't. Even worse when you think its working but it isnt.

 

[EricR]

Hmmm,,, not feeling great about this as I just got the Hanna Alk (dKH) checker the other day (and saw another post where Hanna was way higher than other tests).

First test yesterday vs Red Sea titration test on same water at same time:
Red Sea = 6.0 dKH (been consistent at this for months,,, haven't done anything about it yet)
Hanna = 6.7 dKH

*not as massive a difference but still plan on having my LFS test next time I'm there (and compare again),,, probably next weekend.

 

[FishyFishFish]

Is the ‘clumping’ when the bottle is new? If not, how old is it?

I haven’t had any problems with consistency since following my steps above.

The thing is for many of that have had this issue we can get consistent results repeatedly with one bottle of regeant....then with another bottle get very different(yet consistent with that bottle) results. It points yo an issue with the regeants

Maybe. Maybe not. The accuracy is 0.3 DKH, so presumably you could have 2 readings differ by 0.5 and that is still within the tolerances.

If you open a new bottle and run the 25 tests, and each time you contaminate the bottle (either dropping a bit of water in or leaving it open unnecessarily and it evaporating), and between every 5 tests that contamination changes the reading by 0.1DKH then would you notice? But after 25 tests that has changed by 0.5DKH. Use the last dregs of the reagent and it gets even worse. You then open a new bottle and, holy moly, it is completely different.

I’m not saying that there aren’t differences in the reagents, but I would look at eliminating testing errors first. Opening 2 new bottles at exactly the same time and testing 2 samples back-to-back with perfectly clean and dry vials and syringes would really be the only way to be sure IMO.

Im sure some people have done this and found differences but I’m not sure it is as widespread as the reports would suggest. I find it hard to believe a difference of 4 DKH between 2 uncontaminated bottles, as the OP has suggested, but I could well be wrong.

 

[mdb_talon]

Maybe. Maybe not. The accuracy is 0.3 DKH, so presumably you could have 2 readings differ by 0.5 and that is still within the tolerances.

Nope there is no doubt whatsoever. This is pretty simple. If one bottle consistently reads 9 and another consistently reading 11 then you have an issue with the reagent. These are not minor differences within the MOE we are talking about.

 

[FishyFishFish]

Nope there is no doubt whatsoever. This is pretty simple. If one bottle consistently reads 9 and another consistently reading 11 then you have an issue with the reagent. These are not minor differences within the MOE we are talking about.

All I can say is that I haven’t had anything like a 2DKH difference between 2 bottles.

Maybe I’ve just been lucky.

 

[Woodyman]

I experienced a 4dkh difference between 2 bottles. Side by side testing one after another with Salifert as well.

Same prep, rinse, and everything between the 2 bottles. So it is possible. At the same time though I've only had it happen once in the ~6 bottles I've used personally. Typically they are within 0.5 dkh of each other when cross checking.

 

[mdb_talon]

All I can say is that I haven’t had anything like a 2DKH difference between 2 bottles.

Maybe I’ve just been lucky.

I think most dont run into it to a noticeable amount which is good. However i could duplicate it on three different bottles(out of three) and two of them were unopened until i did my test. That combined to enough stories of similar problems was enough for me to go back to salifert.