ICP Results, Testing and Dosing Questions

[Biokabe]

So I did my first ICP test in a long while and got my results back today (ATI ICP-OES, I'd had a kit lying around for years that I hadn't used).

First issue is my calcium - the measured value is fine, so I'm not worried about that. What I am worried about is that my Salifert test kit (which is what I use to calibrate my Trident) gave me a result that was almost 100 ppm below the actual result. Other than user error (which I won't rule out, but I've done this test hundreds of times so I don't think so), is there anything other than bad reagents that would cause a calcium test to consistently give results that were that far off the actual value? For my last calibration, I performed the test 2-3 times on different days because that number was so low that it seemed suspicious to me (that was what got me to do the ICP test to begin with).

Other than that, ICP identified a few problem areas with other elements: Fluorine, Iodine, Molybdenum, Manganese, Iron, Vanadium and Zinc.

Should I be worried about these elements? Is it necessary to dose them individually, or is something like TM's A- and K+ supplements sufficient?

 

[KrisReef]

I’m not an ICP guru but I would recommend a water change for the minor elements and an immediate replacement for the calcium test.

I don’t generally use API tests but for calcium they seem ok and definitely more reliable than your current Salifert Ca. I generally like salifert but they don’t age gracefully ime. I also just tossed away an older Ca Salifert kit that was also showing low ppms.

Bumps for a better reply

 

[FishLvR]

I'm really curious to see if my poor man's moonshine method works. My results were very similar to your's OP. But no way I was buying each individual and spending over $300. As for calcium isn't 100ppm within error margin? Or is it within 50? I forget.

 

[Randy Holmes-Farley Verified Community Expert]

So I did my first ICP test in a long while and got my results back today (ATI ICP-OES, I'd had a kit lying around for years that I hadn't used).

First issue is my calcium - the measured value is fine, so I'm not worried about that. What I am worried about is that my Salifert test kit (which is what I use to calibrate my Trident) gave me a result that was almost 100 ppm below the actual result. Other than user error (which I won't rule out, but I've done this test hundreds of times so I don't think so), is there anything other than bad reagents that would cause a calcium test to consistently give results that were that far off the actual value? For my last calibration, I performed the test 2-3 times on different days because that number was so low that it seemed suspicious to me (that was what got me to do the ICP test to begin with).

Other than that, ICP identified a few problem areas with other elements: Fluorine, Iodine, Molybdenum, Manganese, Iron, Vanadium and Zinc.

Should I be worried about these elements? Is it necessary to dose them individually, or is something like TM's A- and K+ supplements sufficient?

The icp doesn’t say if dosing TM A and K will be beneficial, but it might be and would be a good experiment.

What were the calcium values in question?

 

[Biokabe]

The icp doesn’t say if dosing TM A and K will be beneficial, but it might be and would be a good experiment.

What were the calcium values in question?

ICP measured at 476, the CA test that I used to calibrate the Trident measured 400 ppm, and the Trident reading from that day was 390.

Since today was my testing day, I did multiple CA tests, including one with the kit that gave me the faulty reading. Today, the kits with older reagents gave me about a 420 reading, and the kit that gave me the faulty reading read about 450, which would be ballpark with the ICP measurement.

So I'm thinking, despite my own confidence, that there may have been some user error after all. Possibly some extra reagent adhering to the outside of the syringe and making its way into the test vial while I wasn't looking, causing the color change to happen earlier than it should have.

I started dosing the A and K today, 3ml each. I have some AFR as well, but since my Alk/Ca/Mg have been relatively stable I don't really want to dose for those until I see an uptick in demand beyond what the water changes supply.