Hanna alk checker
- Thread starter Kfactor
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I have the dKh kit. Easier to work with that number rather than ppm. Also from a how-the-brain-works standpoint, I feel my sanity is better served by .1 dKh precision rather than ppm (mg/l) CaCO3 equivalents. I’d love to know ppm...I really would. But then I would think about small changes too much. .1 dKh units much more practical.
Done correctly, both.
Idoc
Getting lazier and lazier with upkeep!
I like my Red Sea alkalinity titration test, but the directions show the sample changing from blue to red. It never goes red!!!! Oh the frustration...it kind of goes yellow to my eye. Do you have one you like more than the others?
I'm slightly color blind in reds yellow's and I'm sure others. I have a real hard time with all the color change tests, the colors never come close to the included card to my eye so I was just guessing. So I gave up testing except alk with the hanna. I need to get the po4 one next. When will the nitrate one be released? Lol
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Sure you’re reading the right card?
I use this Red Sea Alk pro sometimes.
Red Sea Alkalinity pro test kit - exceptionally high accuracy Test Kit
Red Sea’s KH/Alkalinity Pro Test Kit is an advanced titration test, measuring the level of buffers in your reef aquarium to an exceptionally high accuracy of 0.05 meq/l (0.14 dKH). This test kit enables the accurate dosing of Red Sea's Reef Foundation B supplement (buffer) which is part of the...
www.redseafish.com
If you search, Randy posted a DIY alk test that just uses a calibrated pH meter 100mL of tank water and 0.1M acid. No color change needed. Just read pH to get endpoint. Jim Welsh contributed an awesome pH calibration check in that thread to make it even better. Absurdly accurate.
Normally, that kind of accuracy not needed, but people forget the error is bigger in the Hanna colorimetric method, and start changing their dosing because the Alk “went up/down”.
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From Hanna site.
”Accuracy @ 25°C/77°F ±0.3 dKH [or] ±5% of reading"
So at alk of 10, the uncertainty is actually 0.5dkh.
PatW
2500 Club Member
In my experience, the Hanna checker gives the most reproducible results. The nice thing about it is with competent handling, two people will get the same result.
When I use titration tests, saying exactly when the end point color occurs is a bit problematic.
With the Hanna, I can get very nearly identical results on repeated tests. With interpreting the exact color end point, I am not convinced that I can do better than about plus or minus .2 DKH. Now if I had a spectrophotometer, I could titrate and scan the color spectrum and be objective on exactly when the color peak has hit the right point in the spectrum.
BRS has a you tube video on alkalinity test kits. It was well done. They used multiple testers and compared their results. And the Hanna came out on top.
But heck, if you like a certain test kit, use it by all means. There is more than one way to skin a cat.
When I use titration tests, saying exactly when the end point color occurs is a bit problematic.
With the Hanna, I can get very nearly identical results on repeated tests. With interpreting the exact color end point, I am not convinced that I can do better than about plus or minus .2 DKH. Now if I had a spectrophotometer, I could titrate and scan the color spectrum and be objective on exactly when the color peak has hit the right point in the spectrum.
BRS has a you tube video on alkalinity test kits. It was well done. They used multiple testers and compared their results. And the Hanna came out on top.
But heck, if you like a certain test kit, use it by all means. There is more than one way to skin a cat.
melanotaenia
Well-Known Member
The Hannah checker sucks. It is inconsistent between reagent batches and frustrates me to no end. Get a Salifert kit; the titration color change is easy to see and it is very accurate.
fcmatt
Well-Known Member
I am not sure we are doing the math right there. How can it state plus or minus .3 and then you say it can be off .5?
The way you are doing the math the lower the alk the less the uncertainty.
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Hanna states all their uncertainties as
+-Xconstant +-Y%.
In a thread somewhere on this board they clarified that you should take the larger of the two values. So at low dKH, it's +-.3 and at high dKH (above 6) it's +-5% of the value.
Hanna has always been rock solid in their claims about stated accuracy.
Important not to mistake the smaller meter precision with the larger actual stated accuracy.
Idoc
Getting lazier and lazier with upkeep!
Sure you’re reading the right card?
I use this Red Sea Alk pro sometimes.
In the pic you can see it starts blue and yellow is too far, you can color match to a target green on the card.Red Sea Alkalinity pro test kit - exceptionally high accuracy Test Kit
Red Sea’s KH/Alkalinity Pro Test Kit is an advanced titration test, measuring the level of buffers in your reef aquarium to an exceptionally high accuracy of 0.05 meq/l (0.14 dKH). This test kit enables the accurate dosing of Red Sea's Reef Foundation B supplement (buffer) which is part of the...
If you search, Randy posted a DIY alk test that just uses a calibrated pH meter 100mL of tank water and 0.1M acid. No color change needed. Just read pH to get endpoint. Jim Welsh contributed an awesome pH calibration check in that thread to make it even better. Absurdly accurate.
Normally, that kind of accuracy not needed, but people forget the error is bigger in the Hanna colorimetric method, and start changing their dosing because the Alk “went up/down”.
That's the test I use... and I have a different card!!! What the heck??? I see that green hue and go past it everytime to try to get to red like my card says to do (which is yellow in my samples)... lol
Here's mine:
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Whoa. I think they changed recipe in recent years and it sounds like you have the new chemicals and the old card somehow!That's the test I use... and I have a different card!!! What the heck??? I see that green hue and go past it everytime to try to get to red like my card says to do (which is yellow in my samples)... lol
Here's mine:
