ICP Calcium vs. Test Kit

[Nano sapiens]

Thank you, Ehsan, for the detailed explanation.

Ralph -

 

[msderganc]

Hey guys, maybe I can help you with that a bit.

1. The fluctuations showing up out of our data, in terms of Ca and Mg testing at hom , are quite high. Like Randy said before the Article is not realy far out... but the bigest problem seems not to be the chemicals or different test it is more the human user.

2. For Analytikal reasons therefor you wil get the best results with a "Photometer" to get out the Human error.

3. In our ICP Method your Tests are not tested only once, like Randy said ICP-OES testing of seawater is very difficult. Your tests are actualy caried out 6X and the averge out of them is taken as the result.
Each time we test your for example Calcium, inreality it is detected/tested 2400 Times to create one of the 6 testresults.... So in simple words you can say we test your calcium 2400 x 6 = 14400 Times and then take the average.
This kind of testing make the result quite Accurate... but it is also needed as the conditions are not always Perfect.
So we can say for Calcium we have a + / - 5ppm deviation in the range of 100ppm - 550ppm HTS (High troughput Seawater) copared to a certified standard and NSW and the TRITON Dt controles. but we would also accept a +/- 10ppm.

4.You can addapt the "Methode of often testing" to your own testing if you want. By testing more often and takeing the average you can significantly lower the magnitude of every test method . When you use the human eye as an detector you should also let your Family test some times and take the average then.

5. The 440 setpoint has more a practical reason. in seawater we normaly detect 410, but in the reeftank we think its better to have a smal buffer... as some people forget about dosing or dosingpumps are broken... our Tank is at 480ppm Ca.

6. But the higest instance is still your Tank the testings are only tools to help you decide the right things, so no chasing Nr. like always I would say ( even having my ICP over here)


Hope that helps sorry for the english
All the best Ehsan

Thanks for the thoughtful response, Ehsan. I received my second test results this morning, and my Calcium is reading 430, vs my test on the day I sent of 370 (confirmed with a photometer - Hanna). I can accept that my home tests might be inaccurate, but why are we (almost) always seeing the ICP reading significantly higher than the home tests? I would think that the distribution would be much more evenly spread above and below the true value (ICP, as a proxy).

 

[TheClark]

My Red Sea pro was almost dead on with triton.

664 Red Sea
675 triton

 

[msderganc]

RS calc: 425
Triton calc: 413

I tend to test on end color change not beginning so my test could be 20-40 high.

My Red Sea pro was almost dead on with triton.

Thanks - do you test similar to Sangheili? Or as soon as the color change starts?

 

[TheClark]

Thanks - do you test similar to Sangheili? Or as soon as the color change starts?

My 14 year old does i. (How awesome is that?!!)t. He is very careful, will ask him and post back.

 

[msderganc]

My 14 year old does i. (How awesome is that?!!)t. He is very careful, will ask him and post back.

Very awesome. I can't even train my girlfriend

Am I reading that right? 664 ppm?

 

[TheClark]

Ya, I know, a tad high. [emoji3]