Trident Says Alk 7.54, Hanna says Alk is 8.5

[Lion6]

My hanna matches icp and my buddies trident always reads low.

To my understanding there are four different brands of ICP test you can use. Essentially you are mailing your test to different labs. Do you know which test you mailed in that agrees with your Hannah?

 

[billyocean]

To my understanding there are four different brands of ICP test you can use. Essentially you are mailing your test to different labs. Do you know which test you mailed in that agrees with your Hannah?

Ati icp.

 

[billyocean]

It's important to store hanna reagent in the fridge and shake before each use. Also make sure you have the hi772s reagent.

 

[Lion6]

We have been shaking and refrigerating for all of our tests. For whatever reason we still do not get the same result on our Hanna and our ATI.
My understanding is that every different test for alkalinity has interferences which can change the result.
My current line of thinking is that since every tank has a little different chemistry in the water, maybe our tank water has an interference with the Hanna and yours does not?
Do you think that could be it, or do you think there is some other reason that my Hannah might be different than ATI?

 

[David_CO]

What worked for us:

We were getting a 1.5 dKH lower value on trident than our Hanna alkalinity tester.

The trident was so low that it did not seem believable.

We could not get the Trident to calibrate so it would agree with the Hanna alkalinity tester. When we attempted to calibrate the trident upwards 1.5 dKH using tank water, it seemed to work until the next scheduled test. At the next regularly scheduled test the trident would revert to the values it reported before we had calibrated it.

I SUSPECTED that Trident is programmed to prevented making a large calibration.

I SUSPECTED that if you calibrate more than 1.0 DKH it assumes error and reverts to the last calibration performed with Neptune calibration fluid.

I tried to think of a workaround.

I decided to try to perform a tank water calibration in many different steps. Each time, I only calibrated a portion of the total desired calibration.

It worked and held the values UNTIL I had changed it a total of about 1.0 dKH. After the total of all my calibrations exceeded this 1.0 dKH level, it seemed to throw out all the calibrations and go back to the values it was reporting before I tried to do anything. Back to square one.

Next, I suspected that maybe something else was the cause. The trident comes with a part they call “optional trident sample line filter”. This is a tiny filter about the size of a dime that goes on the end of the sample uptake line that is in your sump. They tell you to use it if you have turbid water and want to keep debris out of the sample line. From the very beginning, we used it because we felt it was good to keep debris out of the trident. I decided that maybe this filter was altering the test results of the trident. I thought maybe the trident had been factory calibrated without this filter attached and maybe adding it could have affected the Trident results. We had never calibrated using anything except tank water before.

I decided that we should calibrate trident using Neptune fluid and WITH THE FILTER IN PLACE.

We performed the calibration with the Neptune fluid and filter attached. Afterwards, the trident was reading only 0.5 dKH less than the Hanna tester. Much closer.

We then performed a ATI-ICP-OES test and the result from ATI matched up very closely with the trident and also was 0.5 DKH lower than Hanna.

Here is my conclusion:

If you are running the “optional trident sample line filter”, try performing a calibration using Neptune fluid with the optional sample line filter in place.

I believe you’ll end up having trident values about 0.5 dKH less than your Hanna alkalinity tester.

I felt that 0.5 difference between Trident and Hanna was a reasonable amount. Since ATI agreed more closely with the trident after calibrating with the filter attached, I now trust the trident and believe the Hanna to be 0.5 dKH high. Regular testing with the Hanna remains consistently 0.5 higher than the trident.

I sincerely hope this can help some of you struggling with large differences between Trident and Hanna for alkalinity. It worked for us.

When I used to use the trident calibration solution I always used the filter and IMO its still a ways off. I've spent a good bit of time comparing alk test kits and from my experience the hanna always reads a little higher then other reference test kits (salifert, red sea and alkatronic) anywhere from .2-.5 dkH.....I believe the best way to calibrate the trident is using tank water with an alk value averaged between several reputable test kits.

I've become less of a fan of the trident over time, I think it needs to run more vial rinse cycles, ive noticed a testing discrepancy when its doing a combined test vs an alk only test. I also find the "second" alk bottle in a 2 month set to sometime contribute a .2-.3 dkh variability when the bottles are switched.

 

[billyocean]

We have been shaking and refrigerating for all of our tests. For whatever reason we still do not get the same result on our Hanna and our ATI.
My understanding is that every different test for alkalinity has interferences which can change the result.
My current line of thinking is that since every tank has a little different chemistry in the water, maybe our tank water has an interference with the Hanna and yours does not?
Do you think that could be it, or do you think there is some other reason that my Hannah might be different than ATI?

I just try to replicate the test in the same fashion every time. Every now and again I soak the vial in vinegar to clean and rinse with ro. Other than that I don't know..as long as it's consistent is all I really shoot for.