Any comparisons or opinions of the Hanna Calcium checker?

[CJO]

Originally Posted by AkaSlyGuy

Not to answer for dowtish, but the extra couple of steps really do not make it harder at all. Just a couple of extra steps that probably take an extra 25 seconds to complete. I like it and I just went ahead and ordered the Alkalinity checker too.

Joe

Thanks for the info.

CJ

[dowtish]

This was posted from a friend who is a chemist.


The Hanna Calcium checker has an operational range of 200-600ppm and the tank water can normally range from 300-500. In order for the Hanna checker to work with the simplified LED spectrophotometer at its set wavelength, the tank water to be tested must be diluted to the checkers measurement range.

The addition of 0.1 mL of tank water to the 10 mL of RODI and Reagent A will give an approximate dilution factor of 1:100

Dilution Factor = sample/sample + RODI + Reagent A
Dilution Factor = sample/total
Dilution factor = 0.1 mL/10.1 mL

The checker reads out in ppm, so it is internally calculating the calcium concentration X 100 by multiplying the absorbance (or transmission) of light through the chemical reaction of calcium displacing zinc and forming a colored complex with the zincon indicator.

This reaction is well documented in laboratories for the measurement of calcium. One note of caution in comparing sample test results.....The accuracy of the Hanna Calcium checker is +/- 6% of the reading. Based on the stated accuracy, the reading of 447ppm will be in the range of 447ppm +/- 27ppm or 420ppm to 474ppm.

Quality control plays a large factor in the accuracy you will get using any test method. You should test a "blank" (or a known zero calcium sample), a standard (a sample with a known calcium concentration), and your tank sample. This will give you an idea of the accuracy of your testing technique and the instrument that you are using.

Once you are comfortable in using this test kit with the Hanna Checker, then it will be more accurate than trying to color compare the test sample with a color card to get a final calcium concentration. It will be more reproducible and consistent in the determination of calcium concentration in your tank water.

[dowtish]

FWIW, I have tested 3 times with RO/DI from my LFS with a TDS of 0, and took it to a friends house and used his RO/DI with a TDS of 2. We got great results with comparison to Salifert kits. I will say this, you MUST follow the instructions perfectly. And the suggestion for pulling a full 1.0 ml into the green syringe, and using 0.1 from the top, so to speak, seems to help. It literally is only 2 drops of tank water.

I am interested to know how much the test is truly affected by the different RO/DI people are using.

[edandsandy]

Anyone else using Hanna test kits?

[maysorum]

I've been using the Hanna ALK and Ca checker for a couple of weeks now. They seem to produce similar results to Salifert, most of the time. I do notice differences between Hanna and Salifert results when I have dosed ALK/Ca (many hours) before testing.

[jtma508]

I'm using the Hanna Ca, Alk and Phosphorous ULR testers and have had them for a couple months. I find them far more consistent than either my Salifert or Elos kits. I do have a laboratory background so I guess I have a leg-up in terms of being comfortable with these kinds of processes. That said, the tests are simple and certainly accurate enough for our tanks. Go slow and follow the directions carefully.

[cnote2991]

Originally Posted by AkaSlyGuy

Ok, the truth is I already had my checker when I posted this, but I was wanting to see what others thought of it because I did not think mine was reading right at first. But come to find out the problem was with me I had forgotten from a long time ago in chemistry class that when reading the water level in a tube, such as the one that comes with the kit, that you read from the bottom of the curve (meniscus) of the water. I was reading the top of the water, not the bottom of the curve (which is actually the water level). Hope that makes sense to someone.

To avoid this problem and make sure I get accurate reproducible results I use a syringe to add the 9ml of RODI water. I belive this makes it more accurate.

I like mine.

[edandsandy]

OK, just got both test kits, right off the bat the lid broke!
I tested my calcium twice and got two different results.....

Also, there is a green and white plunger....which one get which gets which tip?......
This is probably my problem, right


Ed will try one more time and see what he gets... wish us luck!

Ok, I must got a return call from Hanna, the green plunger uses the smaller tip and the white plunger uses the larger tip.

GREAT customer service at Hanna, THANKS!

[solitude127]

Originally Posted by edandsandy

Also, there is a green and white plunger....which one get which gets which tip?......
This is probably my problem, right

They both have their specific tips.

[edandsandy]

Originally Posted by solitude127

They both have their specific tips.

Yes they do... but the directions don't tell you which tip goes where...
I called Hanna and they were a great help...