How often do you guys run ICP tests?

[laverda]

Since I do not do water changes and dose a variety of elements instead, I think they can be useful since their are not hobby test kits to measure everything. Even if their were it would be very time consuming. That said I do not totally trust the results as there have been conflicting results from different companies. So far I have only done one test and it provided some useful data. It confirmed the results of my testing for the most part and made me aware of one element I was over dosing and one I was under dosing. The worst thing is how long it takes to get your results. It would be much better if it only took a day or two. I have only done one test primarily due to the cost as my tank is on a tight budget. The cost really is not that much when you consider how many elements they test. If it did not take so long to get your results I suspect a lot more people would use them considering the time it takes to test a half dozen things and the difficulties reading some tests not to mention discrepancies between the results of different brands of test kits.

 

[Jon Fishman]

I check my tank everyday...... so far no Juggalos.....

 

[Adele]

Just mailed in my first one ever! Excited to see results. Not expecting anything crazy as my system seems in good shape. I was wanting to start adding some trace minerals so figured an ICP first would be best before adding anything.

 

[scott11106]

i have never done one, i would like to see how many people actually do these tests ?

if i had to guess i would only do one if i had a major problem that water changes could not fix??

 

[BestMomEver]

I’ve done them about every 4-6 months just to keep tabs on stuff. I wouldn’t hesitate if things started going south, however.

 

[Rick Mathew]

I send in a sample once every 3 months but my primary purpose is not to measure my tank perimeters, although it does give me data that I do can’t get through my own testing.

My main purpose is to compare my test results to their results. My goal is to improve my testing methods so I don't have to have ICP testing unless something is going on with my system that I can't pinpoint.

I have just recently been sending my samples to 3 different ICP testing services and comparing my results to all 3 as well as comparing them to each other....There are differences, some of which I would consider "significant"

Getting correct value is important because we make decisions on what to do and often take action…If the measurement is wrong we are taking bad actions!

As there has been much discussion about the ICP testing precision and accuracy....

Examples:

Skeptical Reefkeeping article.. http://packedhead.net/2015/triton-lab-icp-oes-testing-of-a-certified-artificial-saltwater-standard/

Dan’s Reef

There are several other posts related to this topic...This presents a problem which one is the correct value?

There is a great deal to be said about the answer to this question but the basics in my opinion are this:

All testing is made up of two goals, Accuracy and Precision….Accuracy is how close to the “real value” is the result…Precision is how reproducible are the results. ICP testing is no different. Tests have several components. Read about it here https://www.inorganicventures.com/accuracy-precision-mean-and-standard-deviation

First is the test device…

Second the test procedure itself…(Weighing, measuring, time, etc.)

Third the sample quality (uniformity, not contaminated etc.)…

Forth the appraiser (person doing the test).

All of these have errors associated with them, both Systematic and Random Errors. In general errors do not compensate, they accumulate all of these components need to be evaluated for error as a whole system. The procedure of Gage Repeatability and Reproducibility, called a Gage R&R is very helpful tool in looking at this accumulative error in the testing results as it relates to precision of the test based on your target value and your allowable error. (Tolerance values) This is an important number. It tells you how far off the target (nominal value) the measurement can be before you have unacceptable results. With regard to reef water testing this depends essentially on the parameter being tested…for example for Calcium a range of 380-450ppm---Range of 70 a 10% tolerance would be ± 7ppm—20% ± 14ppm…etc. So one might set the tolerance at ± 10ppm from the target value of say 415-420pp and feel confident keeping an adequate amount of Calcium in the reef. On the other hand if the parameter is Iodine the range might be 0- .2ppm---10% is .02ppm---20% .04ppm …And being that Iodine can be toxic at elevated levels your allowable error is much smaller.

I won’t go into the details for the Gage R&R Procedure you can read about it here https://quality-one.com/grr/ or here https://www.qualitydigest.com/inside/metrology-article/basics-gauge-rr.html . The math can be quite intimidating but there are a number of free resources that provide Excel Spreadsheets that will do the work for you. …Just Google Gage R&R ANOVA Excel and you will have several options.

I have been using this in my test development projects as well as working to improve my measurements using test kits as well as the Hanna Checkers.

However Precision alone is not sufficient. The measurement need to have good Accuracy, but without Precision it is difficult to know if your measurement it is Accurate without taking a lot of measurements and even then there is a limit to the accuracy no matter how many measurements you take. (A lot of Random errors). This is where reference calibration standards are helpful.

Reference Calibration Standards for our hobby (seawater) are not easy to come by…Especially certified ones…and they are expensive!...Here is an example https://highpuritystandards.com/elements-in-seawater/ (This is the one used in the article by Rich Ross & Dr. Chris Maupin in Skeptical Reefkeeping). There are other ones that you can get but they are not Certified Standards…Like this one http://cm-distributors.com/product/multi-reference-solution/ The point is you have to have an good target in order to know if your test is giving accurate results. So the precision can be high (good repeatability and reproducibility) but it is precisely wrong!

CONCLUSION

Ok, I did not intend to go down the rabbit hole of testing (but I did), but wanted to give some background for this statement.

It would be very helpful to all of us who are interested in Precise and Accurate results of test parameters for our reefs, or like me want to validate my own test results, if the ICP test providers would provide us with Gage R&R (Precision) and Accuracy data on their tests by parameter.

The information may be out there but I have not run onto it. I know that other have done this …Look Here https://www.isixsigma.com/topic/gage-rr-for-icp-spectometer/ The closest I have seen is the article by Rich Ross & Dr. Chris Maupin in Skeptical Reefkeeping (Link Above) ….Although this is not a complete Gage R&R it gives some insight as to the Accuracy of the test results (Table 1) related to each of the elements as well as some level of repeatability (Precision) (3 samples from the same batch). When you take a close look at the Table 1 it is clear that, IMO, that some of the results would be considered accurate and fit for our use while other would not…Not wanting to through the baby out with the bath water…I will take the good ones and reject the inaccurate ones, but more data from all of the providers would be most helpful in helping us to maintain good water quality…IMO.

Sorry for the ramble!!


Rick

 

[MnFish1]

I send in a sample once every 3 months but my primary purpose is not to measure my tank perimeters, although it does give me data that I do can’t get through my own testing.

My main purpose is to compare my test results to their results. My goal is to improve my testing methods so I don't have to have ICP testing unless something is going on with my system that I can't pinpoint.

I have just recently been sending my samples to 3 different ICP testing services and comparing my results to all 3 as well as comparing them to each other....There are differences, some of which I would consider "significant"

Getting correct value is important because we make decisions on what to do and often take action…If the measurement is wrong we are taking bad actions!

As there has been much discussion about the ICP testing precision and accuracy....

Examples:

Skeptical Reefkeeping article.. http://packedhead.net/2015/triton-lab-icp-oes-testing-of-a-certified-artificial-saltwater-standard/

Dan’s Reef

There are several other posts related to this topic...This presents a problem which one is the correct value?

There is a great deal to be said about the answer to this question but the basics in my opinion are this:

All testing is made up of two goals, Accuracy and Precision….Accuracy is how close to the “real value” is the result…Precision is how reproducible are the results. ICP testing is no different. Tests have several components. Read about it here https://www.inorganicventures.com/accuracy-precision-mean-and-standard-deviation

First is the test device…

Second the test procedure itself…(Weighing, measuring, time, etc.)

Third the sample quality (uniformity, not contaminated etc.)…

Forth the appraiser (person doing the test).

All of these have errors associated with them, both Systematic and Random Errors. In general errors do not compensate, they accumulate all of these components need to be evaluated for error as a whole system. The procedure of Gage Repeatability and Reproducibility, called a Gage R&R is very helpful tool in looking at this accumulative error in the testing results as it relates to precision of the test based on your target value and your allowable error. (Tolerance values) This is an important number. It tells you how far off the target (nominal value) the measurement can be before you have unacceptable results. With regard to reef water testing this depends essentially on the parameter being tested…for example for Calcium a range of 380-450ppm---Range of 70 a 10% tolerance would be ± 7ppm—20% ± 14ppm…etc. So one might set the tolerance at ± 10ppm from the target value of say 415-420pp and feel confident keeping an adequate amount of Calcium in the reef. On the other hand if the parameter is Iodine the range might be 0- .2ppm---10% is .02ppm---20% .04ppm …And being that Iodine can be toxic at elevated levels your allowable error is much smaller.

I won’t go into the details for the Gage R&R Procedure you can read about it here https://quality-one.com/grr/ or here https://www.qualitydigest.com/inside/metrology-article/basics-gauge-rr.html . The math can be quite intimidating but there are a number of free resources that provide Excel Spreadsheets that will do the work for you. …Just Google Gage R&R ANOVA Excel and you will have several options.

I have been using this in my test development projects as well as working to improve my measurements using test kits as well as the Hanna Checkers.

However Precision alone is not sufficient. The measurement need to have good Accuracy, but without Precision it is difficult to know if your measurement it is Accurate without taking a lot of measurements and even then there is a limit to the accuracy no matter how many measurements you take. (A lot of Random errors). This is where reference calibration standards are helpful.

Reference Calibration Standards for our hobby (seawater) are not easy to come by…Especially certified ones…and they are expensive!...Here is an example https://highpuritystandards.com/elements-in-seawater/ (This is the one used in the article by Rich Ross & Dr. Chris Maupin in Skeptical Reefkeeping). There are other ones that you can get but they are not Certified Standards…Like this one http://cm-distributors.com/product/multi-reference-solution/ The point is you have to have an good target in order to know if your test is giving accurate results. So the precision can be high (good repeatability and reproducibility) but it is precisely wrong!

CONCLUSION

Ok, I did not intend to go down the rabbit hole of testing (but I did), but wanted to give some background for this statement.

It would be very helpful to all of us who are interested in Precise and Accurate results of test parameters for our reefs, or like me want to validate my own test results, if the ICP test providers would provide us with Gage R&R (Precision) and Accuracy data on their tests by parameter.

The information may be out there but I have not run onto it. I know that other have done this …Look Here https://www.isixsigma.com/topic/gage-rr-for-icp-spectometer/ The closest I have seen is the article by Rich Ross & Dr. Chris Maupin in Skeptical Reefkeeping (Link Above) ….Although this is not a complete Gage R&R it gives some insight as to the Accuracy of the test results (Table 1) related to each of the elements as well as some level of repeatability (Precision) (3 samples from the same batch). When you take a close look at the Table 1 it is clear that, IMO, that some of the results would be considered accurate and fit for our use while other would not…Not wanting to through the baby out with the bath water…I will take the good ones and reject the inaccurate ones, but more data from all of the providers would be most helpful in helping us to maintain good water quality…IMO.

Sorry for the ramble!!


Rick

YOU SHOULD MAKE THIS AN ARTICLE - ITS OUTSTANDING.......... And extremely interesting - for those who just assume their values are 'correct'

 

[Rick Mathew]

YOU SHOULD MAKE THIS AN ARTICLE - ITS OUTSTANDING.......... And extremely interesting - for those who just assume their values are 'correct'

Actually this is just a portion of "the rabbit hole" I am working on putting together a post to put on the site that expands this information to include some examples from my test development and measurement work that will further explain the issue of validating test results. I have some additional data I am gathering and other work on Instrument reference calibration...But you are correct many people take the data from ICP testing as gospel when the reality it is not at least in some cases.

I have also been doing some work with the HANNA Checkers in the same regards....an interesting note on this one is my initial findings, although limited, is that the measurement variability is mostly due to procedural variability (good laboratory practices, clean equipment, etc.), and some other Systematic and Random Errors and not the Checker itself

Thanks for your encouragement!

 

[MnFish1]

I have also been doing some work with the HANNA Checkers in the same regards....an interesting note on this one is my initial findings, although limited, is that the measurement variability is mostly due to procedural variability (good laboratory practices, clean equipment, etc.), and some other Systematic and Random Errors and not the Checker itself

You're welcome - this is also the problem (my guess) that people have with API tests. They are not carefully doing the tests (at least in some cases). I have not had a problem with them.

 

[Rick Mathew]

Not sure... have no data to support it either way... What I have read is that ICP testing is not a simple test and it takes effort to get accurate results...When I was in charge of a fairly well equipped analytical lab it was well known that some tests "A monkey" could do and get good results while others required quite a lot of finesse just to get decent results. We did not do ICP testing we farmed that out to a certified laboratory because we had very few calls for its use....

 

[Ian M]

I ran one ICP test only after a year old tank was killing my test SPS frags and all my home test kits were showing within the normal ranges, the results came back saying all was good. Waited a couple more months and fixed a 5 degree temp swing which I didn't even know about until installing a heater controller and now SPS flourish. Being only a year into the hobby at the time I jumped to it being a water thing not equipment, but having ran one gave peace of mind that my RODI and tanks are chemically stable and made me look elsewhere for stability issues.

Now that i'm a lot more seasoned I will still be hesitant to run another as I believe daily observation and maintenance together with weekly water tests (home kits) once your system is dialed in, negate the need for ICP's in my case. If you have the money to or just want the added security that you are doing it right, I can fully understand that but it is not something I am interested in. Maybe if I owned a coral farm I would do them monthly as it would be for the security/color/health of tens of thousands worth of inventory needed to be perfect to sell and not a small tank in my home.