ICP Testing Showdown! Which one is right???

[webmanny]

Hi all,

I have been wondering if these ICP (Inductively Coupled Plasma) are as accurate as we believe/expect them to be. With that in mind I decided to send sample water to both Triton and ICP-Analysis.com to see how they measure.

Please note that these samples were taken at the same exact time and shipped at the same time. In addition, I also tested the main elements we normally test things at home with my Hanna checker, Red Sea Mag test and API reef master test kit.

To my surprise, the results from both companies don't match in most of the elements we normally test in our tanks or the other test kits we use on a daily basis.

Please note that this is not a jab at any of these companies, as I have no way of confirming which is accurate, but I wanted to share my results with the team, in case you too have been wondering if this is money well spent.

I have attached the official results from both companies and an excel document with the comparison results converted to PPM (Triton posts the results in ug/l)

I hope this at least helps spark the curiosity of someone who can confirm these test results on their own and perform a deeper analysis of this data.

Maybe BRS can do something similar and share it with everyone on their channel.

 

[RobZilla04]

Conclusion first, then my observations. Pick a particular set of tests and/or a particular ICP lab and shoot for consistency over accuracy.

Through the last several weeks of reading articles, watching MANCA presentations, BRS Videos, and other reef YouTube channels it has become obvious that no hobby grade test kit is "better" or "more accurate" than another. The sample size, reagent and method of performance are all subject to much human error. Also each has it's own margin of error which most hobbyist tend to omit acknowledging. The same can be said for the ICP testing labs.

If I've learned anything progressing through this hobby it is to shoot for stability and go slow. Use hobby test kits which work best for you depending on the method of obtaining results. For example I don't see color all that well (red/green deficiency). So I stick with Hannah Checkers, and generally try to maintain a range. Rather than adjust off the hip for a .2 or .3 deviance in dKH, I do nothing. If the next test result trends further in the direction of the first deviance, I start to look at why. Growth and increased consumption? Slowed growth thus dosing accumulation?

Once or twice annually to quarterly is a good frequency to check ICP just to get results for the many elements that we don't have hobby kits for. Compare each ICP to the previous and look for trends within the ranges you find acceptable. Before making off the hip adjustments, evaluate the appearance of YOUR system. If it looks good, do nothing. Chances are you'll cause something bad to happen when nothing needed to be done in the first place.

Here is a good video that references some of what I discuss above:



And another good one from Richard Ross

 

[webmanny]

Very good information. I agree 100%. I never make changes based on results, but rather on how the tank looks.

 

[Cory]

Yeah these icp tests are untrustworthy. Id tend to believe triton since they started first and seem to have a good reputation.

My icp test from marin labs was a bit questionable too. Some things were way off, when it would be impossible unless my salt mix was off. They tested my salinity at 28ppt. I tested my salinity at 35ppt with 3 calibrated devices. Even after asking them to retest they told me to buy another test. For 70$? No thanks.

 

[Cory]

Another thing is how do we know they were right? You cant really. But with my test kit for alkalinity i can make up a batch bicarbonate water and if its 10dkh i know tbe kits working for example.

 

[JimWelsh]

I noticed that, for the major elements, the Triton numbers were consistently 8 to 9 percent higher than the ICP-Analysis numbers. As has been noted, there is no way to tell which, if either, is correct.

I am of the opinion that ICP is probably not the correct tool for trying to determine the major components of seawater. I think it has great value for the more trace elements that are very difficult or impossible for the hobbyist to test for, and, as you can see, Triton and ICP-Analysis largely agree on many of these (e.g., Li, Mo, Ba, Si). But trying to use it for Ca and Mg and other major constituents is a mistake, in my opinion.

 

[Randy Holmes-Farley]

I'm generally not a fan of icp-analysis dot com since when they've discussed issues with their tests here, they seem to have a very poor understanding of chemistry.

 

[webmanny]

I agree with most of you guys and gals above. ICP testing feels like it would be a gauge at best, but that being the case, why send it to a lab in Germany or Colorado so you can get an "estimate" when you can get the same thing from the hobby grade test kits at home.

I will be keeping my money away from ICP test kits until BRS or someone with a better budget than mine can perform a deeper comparison analysis to determine each test's accuracy.

Shout out to the BRS team. Lets see if they are willing to pick this project up for one of their BRStv Investigates episodes.

@randyBRS @Bulk Reef Supply