Is the Hanna Alkalinity Checker really so much faster?

[elysics]

I just did a quick search and got it from the article. If that is true that you ADD them both together, that is quite an error range!

Regarding the "Standard" I understand what it tells you (and understand that perfect user compliance is assumed).

I think the bottom line is, it is almost impossible to get a perfect absolute alkalinity value from any kit. The best that we can strive for is one that seems to "come close" to what one decides is the true alkalinity, and perhaps more importantly, one that will give consistent (reproducible) results. And I guess there are many opinions. My vote is for the Hanna..... the lesser of all the evils, IMO.

I deleted that comment, I'm unsure now myself, the austrian hanna site does write:
"±0.3 dKH or ±5% of reading, whichever is greater". But none of their other sites i looked at do. Now i don't know whether that's due to an confused product description editor, or whether hanna just has a different opinion on how to declare things

 

[stanlalee]

Don't know if it's faster but it's easy and more importantly I get a definitive number. Same with the phosphate meter. Not because it's easy, even though it is, it's because I don't have to give a best guess to color matching like test kits.

 

[Dr. Jim]

I deleted that comment, I'm unsure now myself, the austrian hanna site does write:
"±0.3 dKH or ±5% of reading, whichever is greater". But none of their other sites i looked at do. Now i don't know whether that's due to an confused product description editor, or whether hanna just has a different opinion on how to declare things

Just saw this. Either way, "and" or "or" seems odd. The +/- 5% will always be greater as long as the dKH is above 6.

 

[92Miata]

I deleted that comment, I'm unsure now myself, the austrian hanna site does write:
"±0.3 dKH or ±5% of reading, whichever is greater". But none of their other sites i looked at do. Now i don't know whether that's due to an confused product description editor, or whether hanna just has a different opinion on how to declare things

None of the documents I have with my hanna meters say 'OR' either.

All either say and, or have no word between the two values.

 

[Silent]

No value between on mine. Safe to say whichever value of the 2 is greater would be the accuracy.

 

[mrbacony]

I love the Hanna ULR phosphate checker simply for the fact it is darn near impossible to tell what the amount is with the regular test kits.

But when it come to alkalinity, I just really enjoy the testing process. It is pleasurable for me to do the Salifert test (and pretty quick too). I am sure the Hanna would probably give a more accurate number, but not as enjoyable as doing the titration myself.

 

[Randy Holmes-Farley Verified Community Expert]

It says +/- 5 ppm (0.27 dKH) OR 5% (about 0.4dKH). So the most it should be off is about 0.4dKH. Funny that they word it that way. Why not just the worst case scenario which is the 5%??

BTW, they have a STANDARD that you can use to check your instrument but it seems worthless IMO because the accuracy is +/- 10 ppm (0.56 dKH).

This is from a review:
"Hanna Instruments HI755 advertises accuracy @ 25°C/77°F is ±5 ppm (mg/L) or ±5% of reading, which, in hobby level test kits standards, is highly accurate".

Hanna Instruments Alkalinity Checker- a Definitive Review (reefs.com)

IMO, that's a reasonable way to present uncertainty, because some errors are a fixed dKH/absorbance uncertainty (such as variations in the scattering of the glass from slightly different orientations of the cuvette) and some are a percentage uncertainty (such as variations in the liquid volume measurement).

The 0.27 dKH uncertainty is way more than 5% uncertainty for low alk water.

 

[Randy Holmes-Farley Verified Community Expert]

I just did a quick search and got it from the article. If that is true that you ADD them both together, that is quite an error range!
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EDIT: Hey, I just noticed you edited your post. Does that mean you DON'T think the two "accuracies" should be added?
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Regarding the "Standard" I understand what it tells you (and understand that perfect user compliance is assumed).

I think the bottom line is, it is almost impossible to get a perfect absolute alkalinity value from any kit. The best that we can strive for is one that seems to "come close" to what one decides is the true alkalinity, and perhaps more importantly, one that will give consistent (reproducible) results. And I guess there are many opinions. My vote is for the Hanna..... the lesser of all the evils, IMO.

You do not add the two uncertainties. They both apply independently and you look to the higher one.

That said, those uncertainties are when you are an expert user and the kit is working perfectly.

If either of those is untrue, the actual uncertainty may be way off.

 

[Randy Holmes-Farley Verified Community Expert]

Just saw this. Either way, "and" or "or" seems odd. The +/- 5% will always be greater as long as the dKH is above 6.

Yes, but the device claims a suitable range all the way from 0 dKH (0 ppm) to 16.5 dKH (300 ppm).

 

[MichaelReefer]

So everyone always touts the alkalinity checker as being super fast and better than titration, is that really the case? I only have got the phosphorous ulr, but with the amount of babying it takes to keep those vials pristine, it would seem to me like titration is just faster? Or am i missing something? Including walking around, rinsing a random vial twice with rodi and once with tank water beforehand and thrice with rodi after, it takes me less than 2 minutes to perform the salifert one, at a quarter of the cost of just the hanna reagents.

It takes me like two minutes to do my Hanna test...lol

 

[Lovefish77]

Just tried another test with salifert (using another kit I have) drawing the reagent so the liquid fills till 0.85 mark....did not make any difference on results. Still 1 dkh lower than hanna 755. If hanna is correct that proves why sps crashed with low nutrients.

 

[Montiman]

Just tried another test with salifert (using another kit I have) drawing the reagent so the liquid fills till 0.85 mark....did not make any difference on results. Still 1 dkh lower than hanna 755. If hanna is correct that proves why sps crashed with low nutrients.

While there is truth in this statement the lesson I take from this is why shoot for borderline alk? An alk of 8-10 even if off by 1 DKH is fine. Shooting for 7 or 7.5 is trouble if you ask me.

Any test kit could easily be off by 1 DKH for any number of reasons. Rather than complain I prefer to build this uncertainty into my reefing methodology.

Once again it would be great if we had more accurate testing methods. I am sad for your loss and can relate as I have been through similar problems with test kits reading incorrectly or a bad refractometer. I still believe it is best to acknowledge the flaws in our current testing methods and learn to live with them rather then demand a perfect testing solution.

 

[Lovefish77]

While there is truth in this statement the lesson I take from this is why shoot for borderline alk? An alk of 8-10 even if off by 1 DKH is fine. Shooting for 7 or 7.5 is trouble if you ask me.

Any test kit could easily be off by 1 DKH for any number of reasons. Rather than complain I prefer to build this uncertainty into my reefing methodology.

Once again it would be great if we had more accurate testing methods. I am sad for your loss and can relate as I have been through similar problems with test kits reading incorrectly or a bad refractometer. I still believe it is best to acknowledge the flaws in our current testing methods and learn to live with them rather then demand a perfect testing solution.

Thanks but what dkh would you shoot for if 7 to 7.5 is high? Let me know please
Just an update I called Hanna instruments today and I guess the guys at BRS drove me to a brick wall; I have the 755 checker and only found 772 reagent at brs and they confirmed it will work on 755!!! Hanna instrument just said that this is wrong, you just gotta do your checks with everything. Some of those guys dont know what they are saying really..

 

[Montiman]

Thanks but what dkh would you shoot for if 7 to 7.5 is high? Let me know please
Just an update I called Hanna instruments today and I guess the guys at BRS drove me to a brick wall; I have the 755 checker and only found 772 reagent at brs and they confirmed it will work on 755!!! Hanna instrument just said that this is wrong, you just gotta do your checks with everything. Some of those guys dont know what they are saying really..

If 7-7.5 is high then your nutrients are too low.

But I understand what you are getting at. Running an ULNS requires low alk and has some benefits. To me running an extremely low alk and extremely low nutrients is asking for trouble. Running moderate alk and moderate nutrients is just much safer.

 

[Lovefish77]

If 7-7.5 is high then your nutrients are too low.

But I understand what you are getting at. Running an ULNS requires low alk and has some benefits. To me running an extremely low alk and extremely low nutrients is asking for trouble. Running moderate alk and moderate nutrients is just much safer.

Please give me the recipe lol been looking for that answer for ages
I thought ultra low nutrients and alk above 8 is asking for trouble though (contrary to what you are saying)

 

[Montiman]

Please give me the recipe lol been looking for that answer for ages
I thought ultra low nutrients and alk above 8 is asking for trouble though (contrary to what you are saying)

Correct.

My solution is do not run Ultra Low Nutrients. Again I fully understand why people want to, but to me running on the extreme end of what is acceptable makes me nervous.

 

[Lovefish77]

Correct.

My solution is do not run Ultra Low Nutrients. Again I fully understand why people want to, but to me running on the extreme end of what is acceptable makes me nervous.

But tried to jump off extreme low nutrients for ages and it crashed the tank.