Hanna copper checker

[mrcote1]

I was wondering if anyone has experience using the Hanna Instruments copper checker with coppersafe? I was using the API test kit and it looked like I was between 1.5ppm and 2ppm but I bought the Hanna checker to be safe and that said I was at 3ppm. This did not make very much sense since my clownfish and blenny was doing great. But I did a 20% water change anyways and brought it down to about 2.5ppm. And now white spots are showing back up? Should I not trust the Hanna Checker?

 

[aresangel]

Unfortunately many of the handheld devices have a fairly high margin of error. Having a +- error in the device makes it very hard to trust. I used to work on a 25,000 x-ray fluorescent spectrometer and if we had reading that low in the 1-10ppm it often had a margin of error of +-2-3 ppm. So essentially we could not say that the metal was present in the sample.

If they were recording ppb and reading in ppm then there is going to be a large margin of error as well. I always worry about electronic calibration as well.

For very small numbers I would trust a direct titration reading test kit. One where it measures tenths of a ml and can be viewed by a chart.

Sorry to not really answer your question... but I would look into the Hanna manual and see what the margin of error is and if there is a calibration solution that you can check it’s accuracy.

Tim


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[mrcote1]

The error is +- 0.05ppm at 77 degrees so the margin of error is not an issue here since my wiggle room is .5 ppm. They do sell a calibration cuvette for $20 which I feel is a bit crazy. But even if it was calibrated to that im not sure I could trust it since the Hanna checker was not originally designed to test the type of copper we use from what ive read. Should my fish be dead from 3ppm of copper? If not maybe im just terrible at reading the API but thats a pretty big color difference on the chart

 

[mrcote1]

Here are pictures of the clownfish. Its been a little over a week since copper treatment and when I lowered to "2.5ppm" according the hanna checker these spots showed up the next day.

 

[dz6t]

The error is +- 0.05ppm at 77 degrees so the margin of error is not an issue here since my wiggle room is .5 ppm. They do sell a calibration cuvette for $20 which I feel is a bit crazy. But even if it was calibrated to that im not sure I could trust it since the Hanna checker was not originally designed to test the type of copper we use from what ive read. Should my fish be dead from 3ppm of copper? If not maybe im just terrible at reading the API but thats a pretty big color difference on the chart

That margin of error is what the manufacture claimed. That kind of accuracy normally does not come with a $50 device, Or you will see these cheap checkers in scientific labs. I personally do not use colorimetric device when a titration method is available.


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[mrcote1]

How complicated is the titration method? Im not familiar with it and a google search doesnt help much. My chemistry background is limited

 

[dz6t]

Salifert makes a copper test kit which is good.


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[aresangel]

Titration just means you have a measured pipette that you fill completely then slowly add solution to a mixture. When the color changes from one color to another you read the remaining amount on the pipette. This lets you know the concentration when comparing to a chart or a multiplication factor. Ex. At .42ml then copper is x. Or it might be , take the remaining about and multiply it by .0525. So if you have .5ml left then you would have a concentration of 0.02625


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[mrcote1]

Oh okay, so this is how the salifert test kit works?

 

[dz6t]

Yes, salifert is a titration test kit.



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[mrcote1]

Perfect thank you! Ill look into getting one as well. I spoke to Hanna instruments aquarium specialist and he assured me their product is very accurate with coppersafe and it is common that people say the API has lower results than the hanna.

 

[phg1960]

Salifert is a good copper test kit, but it is not titration method. You get a reading by combining water and chemicals then wait 10 minutes and compare color to a reference. I may be color blind, since I can never find a good match.

 

[mrcote1]

That does look slighty easier to read than API but it does look like there is still a lot of room for reading errors it looks. Id assume that reading is .5 though

 

[jah-hoeva]

The Hanna copper checker has been doing fairly well in testing on R2R as far as accuracy goes with a variety of copper medications. FYI