Thank you Sara. I had the best intentions to get a flu shot but waited until it was too late.Hello.
Can’t wait to read this and good thing I stared on the last page . Hope your feeling better @Dana Riddle.
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Thank you Sara. I had the best intentions to get a flu shot but waited until it was too late.Hello.
Can’t wait to read this and good thing I stared on the last page . Hope your feeling better @Dana Riddle.
Thank you Lasse.OK - it means that Hanna alkalinity checker is rather good and accurate. Now someone have to compare Hanna with some of the standard hobby tests that use titration.
Have a speedy recover Dana
Sincerely Lasse
Thank you Sara. I had the best intentions to get a flu shot but waited until it was too late.
Worked like a charm Lasse! Thank you!
Mr Riddle,
Thank you for going through with this series of tests.
I'm curious though as to why you did not compare the results from both checkers to known value samples in order to determine accuracy. I realize these are hobby grade test kits and are going to have a margin of error that is substantially larger than a lab grade test protocol and equipment, but it would have been nice to have IMO.
ETA - sorry to hear of your bout with the flu, glad you're feeling better.
Essentially he took the Hach as the reference standard.No attempt was made to compare results of either result sets to a known standard. Since Hach’s method for alkalinity determination conforms to that described in the 14th edition of Standard Methods for the Examination of Water and Wastewater, I am operating under the assumption that it generates accurate results.
Hanna has an alkalinity standard available for $20, plus tax & shipping. I'll add that to the next order I make.Mr Riddle,
Thank you for going through with this series of tests.
I'm curious though as to why you did not compare the results from both checkers to known value samples in order to determine accuracy. I realize these are hobby grade test kits and are going to have a margin of error that is substantially larger than a lab grade test protocol and equipment, but it would have been nice to have IMO.
ETA - sorry to hear of your bout with the flu, glad you're feeling better.
I looked at Hanna's site, and see the reagent sets have different numbers, although the methods appear to the the same. I think the difference is actually the multiplier programmed into the different Checkers.Dana - I've had influenza before and it SUCKS! I hope you're feeling better.
Regarding the article, I looked at Hanna's web site and note that the 772 (dKH) and 775 (ppm) checkers use different reagents. I had assumed that they did the same test and just calculated/displayed the results differently, but if they don't, the accuracy & precision of the two checkers is not necessarily the same. I have the 772 dKH checker and when I ran 6 consecutive tests on the same water it gave the same results for 5 of the 6 tests and the 6th test only differed by 0.1 dKH, so I can at least confirm that it's precise.
Do you have the actual results from the tests that you graphed? looking at the graph, it looks like the results. for the 130 ppm standard were the same, for the 136 standard the Hanna looks like it's about 7 ppm/5% higher, for the 162 standard it looks about 2 ppm/1% higher, and for the 190 standard it looks like its about 6 ppm/3% higher. Interestingly, for the 190 and 162 standards the Hanna actually read closer to the stated value than the Hach.
Also, did you perform multiple tests on each sample to assess the precision of each method?
Yeah, that's what I assumed. It's possible that the two reagents are actually the same and hanna just numbers them differently to avoid confusion for people, but I would have guessed that they would simply put both numbers on the bottle.I looked at Hanna's site, and see the reagent sets have different numbers, although the methods appear to the the same. I think the difference is actually the multiplier programmed into the different Checkers.
Sorry - I missed that. Either way, given the price and ease of testing the Hanna checker is impressive!I ran several tests at each alkalinity value with the Checker (as stated in the Discussion section.) Note the article states results at 162 mg/L CaCO3, but I forgot to take a photo and ran the test for a 4th time which generated a result of 161 mg/L - see Figure one in the article.
Hanna has an alkalinity standard available for $20, plus tax & shipping. I'll add that to the next order I make.
I appreciate your comments. The gist of the article was to compare results obtained with the Hach titration method (which I have used for years in both marine aquaria and operations of various water treatment plants with success) to those reported by the Hanna colorimeter. This is actually the second time I've compared results - the other was for a MACNA presentation I made a few years back - 2015, I think. Bottom line - I trust the Hanna Checker to deliver valid results, without all the bother of calibrating the pH meter, titration, cleaning glassware, etc.Hmm...
I typed up a nice post about how I would appreciate you doing this...then realized that you doing the test was great for informational purposes, but wouldnt help me determine if my own personal Hanna DKH Checker was accurate.
So I went looking and found this:
https://www.bulkreefsupply.com/hi772-11-alkalinity-dkh-calibration-check-set.html
But, one of the reviewers made a great point about that product not being able to help with variations in the reagent from batch to batch.
Which brings up the question: Why bother testing for it then?
Not in terms of negativity, but rather...realize this is a hobby grade test kit and will only be so accurate, no matter what.
And if the reagent is off, you're going to get skewed results that you cannot test for. Additionally, how accurate does a hobby grade test kit have to be order to be successful and telling us (hobbyists at home) what the parameters are?
Without taking too much effort it would be easy to go down the rabbit hole of chasing numbers and getting frustrated.
I think it's easier to plan for a little acceptable deviation and roll with it.
Hope that makes sense...I work a rotating shift and am on midnights right now so my sleep is off and I may be a few bubbles off center.
Still under the weather, with a hacking cough. Gee, I've never been down with the flu for this long... I'll order the Hanna alkalinity standard and add it as an addendum to the article.Thank you again for your reply.
I figured that was the bottom line of your testing the two together.
I appreciate your time and efforts.
Hope you're fully recovered from your bout with the flu.
Still under the weather, with a hacking cough. Gee, I've never been down with the flu for this long... I'll order the Hanna alkalinity standard and add it as an addendum to the article.
Thank you. I'm going Friday. To those who haven't gotten the flu shot, please do so.If you haven't done so already, please go see a doc.
Still under the weather, with a hacking cough. Gee, I've never been down with the flu for this long... I'll order the Hanna alkalinity standard and add it as an addendum to the article.