How We Use ICP-OES Results Of Unknown Accuracy And Precision

[Lasse]

I will also say that Lasse is an expert aquarist that could have probably had success sending in old water that boiled pasta for ICP. He is smart and experienced and could identify and withstand any type of garbage result.

Thank you - even if it is not entirely truthful. Yes - I can use my brain and experiences to sort out many different things and know that one single result is not to be trusted. But ICP is one of my tools and it helps me to tune in the system. It give me a validation of my hobby tests.

My worry is for those who are newer or less experienced looking to trust something like this as an absolute, so well-done to express that this is not a good idea without more digging. I have seen too many ICP tests cause harm in various ways. ICP is just a tool and it needs to be used correctly.

This is an interesting point of attack because it rise the question of how much harm the use of normal hobby aquarium tests have done (and do). IMO - it is not a question of method - is a question how much we should rely on hobby test results (or ICP) compared to all the other things we can consider in our aquarium. The most common line when someone posts a problem is "What measurement values do you have" - NO3 and PO4 in particular. From the answer to this question, a whole bundle of advice is formed based on these individual measured values. Or when someone posts - I have 0.5 in phosphate. There are seldom answers that ask - what does your aquarium look like but the vast majority of answers are as follows - lower the value immediately otherwise harmagadon occurs. We seldom says - if you use a Hanna low phosphate test and read 0.04 - your real result can be between 0 and 0.08 ppm. It means that a reading of 0.04 means that your result can be both the "catastrophic" 0.08 or the "catastrophic" 0.00.

You definitely don't need ICP to keep easy corals like yours.

I´m keeping all kinds of corals and some SPS tanks for 22 years without ICP. I doubt that ICP can help my tank look better.

Best Regards

I do not agree at all - it 4 years of no WC at all. I am totally depended of additives. Without these more than 25 ICP analyses I had been total blind and the aquarium have crashed either by overdosing or underdosing, but most likely because of both. Easy or difficult corals does not matter - they create biomass and the building blocks for this biomass is taken partly from the water column. I would say that the problem is much worse in an aquarium like mine - with high biomass - because of the fast growth that risk to deplete the water from different compounds. During this time - i have had 4 clams - growing up from some grams to beasts around 3 kg - in 4 years. In my ICP tests - high values of metals and trace elements is not of any huge concern - but I consequently run low in compounds that both actively dose (each day) or compounds that I add after the ICP result.

I can say that i have drive for 65 years . Most of the without a rear view camera - but man - how much easier it is with this camera I get when I bought a new car 5 years ago. No more guessing - I see the distance and the walls in my garage

Sincerely Lasse

 

[Rick Mathew]

Thank you - even if it is not entirely truthful. Yes - I can use my brain and experiences to sort out many different things and know that one single result is not to be trusted. But ICP is one of my tools and it helps me to tune in the system. It give me a validation of my hobby tests.


This is an interesting point of attack because it rise the question of how much harm the use of normal hobby aquarium tests have done (and do). IMO - it is not a question of method - is a question how much we should rely on hobby test results (or ICP) compared to all the other things we can consider in our aquarium. The most common line when someone posts a problem is "What measurement values do you have" - NO3 and PO4 in particular. From the answer to this question, a whole bundle of advice is formed based on these individual measured values. Or when someone posts - I have 0.5 in phosphate. There are seldom answers that ask - what does your aquarium look like but the vast majority of answers are as follows - lower the value immediately otherwise harmagadon occurs. We seldom says - if you use a Hanna low phosphate test and read 0.04 - your real result can be between 0 and 0.08 ppm. It means that a reading of 0.04 means that your result can be both the "catastrophic" 0.08 or the "catastrophic" 0.00.


I do not agree at all - it 4 years of no WC at all. I totally depended of additives. Without these more than 25 ICP analyses I had been total blind and the aquarium have crashed either by overdosing or underdosing, but most likely because of both. Easy or difficult corals does not matter - they create biomass and the building blocks for this biomass is taken partly from the water column. I would say that the problem is much worse in an aquarium like mine - with high biomass - because of the fast growth that risk to deplete the water from different compounds. During this time - i have had 4 clams - growing up from some grams to beasts around 3 kg - in 4 years. In my ICP tests - high values of metals and trace elements is not of any huge concern - but I consequently run low in compounds that both actively dose (each day) or compounds that I add after the ICP result.

I can say that i have drive for 65 years . Most of the without a rear view camera - but man - how much easier it is with this camera I get when I bought a new car 5 years ago. No more guessing - I see the distance and the walls in my garage

Sincerely Lasse

"This is an interesting point of attack because it rise the question of how much harm the use of normal hobby aquarium tests have done (and do). IMO - it is not a question of method - is a question how much we should rely on hobby test results (or ICP) compared to all the other things we can consider in our aquarium. The most common line when someone posts a problem is "What measurement values do you have" - NO3 and PO4 in particular. From the answer to this question, a whole bundle of advice is formed based on these individual measured values. Or when someone posts - I have 0.5 in phosphate. There are seldom answers that ask - what does your aquarium look like but the vast majority of answers are as follows - lower the value immediately otherwise harmagadon occurs. We seldom says - if you use a Hanna low phosphate test and read 0.04 - your real result can be between 0 and 0.08 ppm. It means that a reading of 0.04 means that your result can be both the "catastrophic" 0.08 or the "catastrophic" 0.00."

Lasse,
This point above is spot on!! Every measurement regardless of the type...the manufacture...or what ever is variable. The question is how much? If we know the answer to this question we can then proceed to to take action or not...To Ignore or not...to be concerned or not. If we do not know the answer to the question we are as you say potentially heading toward " harmagadon" This is true for all measurement types ICP or otherwise...People with experience like you can assess these measurement through years of experience and make wise decisions as to what actions to take whereas others can not. You are also correct that it is likely that poor measurement kits and or methods has created lots more harmagadons then ICP has... Chasing a random number generator can create all kinds of instability in a tank!

Our overall purpose was not to answer the question "Should I use ICP to manage my water parameters"... but how much variability can I expect from an ICP measurement and how could I effectively use these measurements to best make decisions about my system, my own testing results etc. without having many years of experience...

 

[Lasse]

Our overall purpose was not to answer the question "Should I use ICP to manage my water parameters"... but how much variability can I expect from an ICP measurement and how could I effectively use these measurements to best make decisions about my system, my own testing results etc. without having many years of experience...

I wrote my post early in the morning - before my third espresso. I forgot the most important thing in this thread - the dep understanding of pros and cons with ICP testing that you get reading the article . Thank you for this article.

Sincerely Lasse

 

[jda]

To clarify my point, as well... I think that ICP is a fine tool. People just need to know how to use that tool.

I also see home testing and ICP as a false equivalency. Sure, both can result in issues, but when I pay an expert, I have a different expectation. If I hire a wealth manager and they want a cut of my money, they need to do a better job than me. The same with a mechanic - if I replace the transmission in my kids SUV and I have a bolt and clamp left over, then that is fine, but I am not happy if a $150 a hour pro does the same.

I just see too many that are having issues looking to ICP for a smoking gun and they never get one. They spend the time (weeks?) waiting and usually end up with more questions than answers. None of them look at the results and think 'this is fine' since they know that their tank is suffering. I like that this article helps explain what they might expect if they choose to do this.

 

[Randy Holmes-Farley]

To clarify my point, as well... I think that ICP is a fine tool. People just need to know how to use that tool.

I also see home testing and ICP as a false equivalency. Sure, both can result in issues, but when I pay an expert, I have a different expectation. If I hire a wealth manager and they want a cut of my money, they need to do a better job than me. The same with a mechanic - if I replace the transmission in my kids SUV and I have a bolt and clamp left over, then that is fine, but I am not happy if a $150 a hour pro does the same.

I just see too many that are having issues looking to ICP for a smoking gun and they never get one. They spend the time (weeks?) waiting and usually end up with more questions than answers. None of them look at the results and think 'this is fine' since they know that their tank is suffering. I like that this article helps explain what they might expect if they choose to do this.

On the smoking gun issue, I think that aside from accuracy, that’s the biggest issue in interpreting icp and toxicity.

How much of anything is too much? What chemical form is actually present? What organisms are sensitive to that specific form of that specific chemical at that concentration?

It’s a far more complicated question than “Is 47 ppb Tin too much?”

 

[Rick Mathew]

On the smoking gun issue, I think that aside from accuracy, that’s the biggest issue in interpreting icp and toxicity.

How much of anything is too much? What chemical form is actually present? What organisms are sensitive to that specific form of that specific chemical at that concentration?

It’s a far more complicated question than “Is 47 ppb Tin too much?”

This is soooooo true....The hunt for the "magic" number can become an obsession...Simple solutions to complex problems seldom exist ....At least that has been my experience.

 

[psiconauta]

so out of all the companies, which was the "most" trustworthy and which the "less"

 

[Rick Mathew]

so out of all the companies, which was the "most" trustworthy and which the "less"

The answer to your question is not so straight forward. As the results show all of the vendors have their strong points and challenging ones. That is why the analysis had to be done to look at the results by element. For example if you you look at chart # 5 you can see that all of the vendors do quite well at the precision measurement of Potassium (K). Whereas looking at chart # 8 all of the vendors do a poor job of the precision measurement of Phosphorous (P). Also on chart # 8 you can see that in the measurement of Iodine (I) you can see different levels of performance by vendor.

Our overall purpose was not to answer the question which vendor is best or worse, but how much variability can I expect from an ICP measurement and how could I effectively use these measurements to best make decisions about my system, my own testing results etc. without having many years of experience...

All of that being said I will note that ICP Analysis appears to have had some challenges with this study. I you carefully review the outcomes you will be able to observe this. To differentiate and rank the others would beyond the scope of this work....Thanks for the question

 

[Dan_P]

The answer to your question is not so straight forward. As the results show all of the vendors have their strong points and challenging ones. That is why the analysis had to be done to look at the results by element. For example if you you look at chart # 5 you can see that all of the vendors do quite well at the precision measurement of Potassium (K). Whereas looking at chart # 8 all of the vendors do a poor job of the precision measurement of Phosphorous (P). Also on chart # 8 you can see that in the measurement of Iodine (I) you can see different levels of performance by vendor.

Our overall purpose was not to answer the question which vendor is best or worse, but how much variability can I expect from an ICP measurement and how could I effectively use these measurements to best make decisions about my system, my own testing results etc. without having many years of experience...

All of that being said I will note that ICP Analysis appears to have had some challenges with this study. I you carefully review the outcomes you will be able to observe this. To differentiate and rank the others would beyond the scope of this work....Thanks for the question

Rick, I still half seriously suggest that testing a sample in triplicate at ICP-A is more informative than a single test by any other vendor. With an estimate of the variance for each element for nearly the same price, you are obtaining information to tell you what noisy data to ignore. What you ignore will likely vary every time you test though. Couple this with Randy’s observation that given an element’s concentration, no one really knows whether it is causing a problem or not, the strategy might actually be optimal

 

[Sean Clark]

ICP-A dropped sulfur from their tests for some reason. I used them a lot in the past. I'll use someone that reports sulfur in the future.

 

[Rick Mathew]

Rick, I still half seriously suggest that testing a sample in triplicate at ICP-A is more informative than a single test by any other vendor. With an estimate of the variance for each element for nearly the same price, you are obtaining information to tell you what noisy data to ignore. What you ignore will likely vary every time you test though. Couple this with Randy’s observation that given an element’s concentration, no one really knows whether it is causing a problem or not, the strategy might actually be optimal

Dan, I think this suggestion is worth pondering. The question of if the variability is very large, 3 samples may not be enough to get a clear picture of what to ignore is the one I get stuck on. Looking at the data results there are for sure some elements that your suggestion would be valuable to employ, but as you point out you may adjust what you will ignore every time you test depending on the variability of the 3 measurements...

 

[Dan_P]

Dan, I think this suggestion is worth pondering. The question of if the variability is very large, 3 samples may not be enough to get a clear picture of what to ignore is the one I get stuck on. Looking at the data results there are for sure some elements that your suggestion would be valuable to employ, but as you point out you may adjust what you will ignore every time you test depending on the variability of the 3 measurements...

Thanks for straightening me out. It might have been the recent ICP-A sale that got me thinking about this again

 

[Rick Mathew]

Thanks for straightening me out. It might have been the recent ICP-A sale that got me thinking about this again

 

[Snoopy 67]

When this testing first arrived on the scene I was told by an experienced aquarist, " this is just another tool in our toolbox, it is Not the holy grail of information".

 

[Rick Mathew]

When this testing first arrived on the scene I was told by an experienced aquarist, " this is just another tool in our toolbox, it is Not the holy grail of information".

Good point....They are correct and like any tool it needed to be used where it best fits and preforms.

 

[Dan_P]

Good point....They are correct and like any tool it needed to be used where it best fits and preforms.

Darn those experienced reefers!