API vs Hanna
- Thread starter TurboReef
- Start date
TurboReef
Guest
Bassed on reef keeper experience I trust it. API has been known to be inaccurate on “some” tests.
Vhuang168
Guest
So you didn't qualify the accuracy. Just based it on what number you expected to see? Not trying to difficult, just trying to get more information on why some tests are deemed more accurate than others.
I often see this. No actual tests to confirm that 1 test is more accurate than another, other than the 'better' test shows a result closer to the expected number than the other. Thus that is the 'better' one.
Though in your case, I would say that yes the Hanna is probably more accurate since it takes the human eye out of the equation. But without actually testing it, it is at best an educated opinion on my part.
I often see this. No actual tests to confirm that 1 test is more accurate than another, other than the 'better' test shows a result closer to the expected number than the other. Thus that is the 'better' one.
Though in your case, I would say that yes the Hanna is probably more accurate since it takes the human eye out of the equation. But without actually testing it, it is at best an educated opinion on my part.
TurboReef
Guest
To be fair you could say the same about the trident system. Many consider the hanna system to be more accurate. How are they quantifying that? For that matter who is to say that brand a, b and c are either less or more accurate than each-other without a third party testing to a scientific standard.
- Randy
Vhuang168
Guest
That is exactly my point. Without actual testing, how is one to know which is more accurate? I always advocate testing against known standard. Before the Trident, everytime I change to a new reagent set for any test kit I was using... be it Hanna or Red Sea or Salifert, I test it against a reference solution if I can find one with the parameters needed. That way I know what the deviation is.
Mike Yasin
Guest
I'm showing my wife this reply. She thinks I'm batty because I test at reagent swap. "why are you testing? Isn't that what that $600 machine is for?" lol
TurboReef
Guest
That is exactly the issue I have with spending the money for the triton. If I have to test every-time I load up new re-agents than something fundamentally seems wrong. Hanna I am sure has thousands of batches of re-agents. I don't see anyone testing those for accuracy.
Mike Yasin
Guest
Over all the Triton saves me a ton of time. I have become to trust it more and more over time, and turn over a percentage based control over dosing Alk and Cal to make up for small parameter swings, leaving larger ones for me to figure out. To me, a Triton paired with DOS is a very good example of applied reef automation.
NanoCrazed
Supporting Member
On a related note, be sure to calibrate your hanna meters from time to time. both the device, and other variables like dirty cuvettes, etc can affect your readings...not to mention window of error / accuracy per device / test.
Vhuang168
Guest
You calibrate using the included calibration solutions. You can then run a combined test with the solution to verify calibration.
I can tell you from personal experience verifying results of different batches of Hanna reagents that they vary from batch to batch. All within their established ranges but each batch is different from other batches.
Why? Have you quantified the accuracy of said tests?
I suggest you get a bottle of reference solution and test it using your prefered testing methods. If you can stop yourself from looking at the parameters listed on the bottle before you test will make it an even better test of accuracy.
NanoCrazed
Supporting Member
They easy test is to test a reference standard on both. or even the same sample to compare relative ranges.
In most cases, my Hanna and Trident measurements are spot on or pretty close for the things the two tests in common. (I've done the comparison recently... )
Vhuang168
Guest
You cannot calibrate a Hanna checker. You can however verify that the checker will read to within its range. The colored cuvette has liquid that is tinted to the equivalent of 100 +/- 10 ppm or 90ppm (5.03dkh) to 110 ppm (6.15dkh). So all you can do is see that your checker reads somewhere between those 2 extremes. If it does, it is working as intended.
NanoCrazed
Supporting Member
Sorry -- left out teh word "check" in my sentence.. But yes -- you are correct... it's a reference sanity check
rygh
Guest
API, and most others, can be WAY OFF as reagents get old.
Various chemicals precipitate.
Water evaporates through imperfect caps.
Crud accumulates on tip, affecting drops.
User does not shake it enough.
Etc.
The electronic hanna checkers uses dry individual packets, so should be less susceptible to that.
API is super cheap, and you can have Amazon auto deliver a new one every 2 months, so is "in a way" less susceptible as well.
---
As far as which is "correct" : The only way is to test with a highly accurate, reliable, NEW, calibration fluid. But for Alk/Ca/Etc, those are not
something you see at LFS.
Various chemicals precipitate.
Water evaporates through imperfect caps.
Crud accumulates on tip, affecting drops.
User does not shake it enough.
Etc.
The electronic hanna checkers uses dry individual packets, so should be less susceptible to that.
API is super cheap, and you can have Amazon auto deliver a new one every 2 months, so is "in a way" less susceptible as well.
---
As far as which is "correct" : The only way is to test with a highly accurate, reliable, NEW, calibration fluid. But for Alk/Ca/Etc, those are not
something you see at LFS.
Vhuang168
Guest
So taking what you said and applying to itself, how would you check your Hanna for accuracy? Not taking about precision, accuracy.