ICP Test Accuracy

[chadfish]

So my partial tank crash got me thinking about trying an ICP test. @dz6t turned me on to the Skeptical Reefer. This article is from 2014. It shows the flaws in the Triton ICP test of the day. Has anything changed since then?

Skeptical Reefkeeping 12

Triton Lab ICP-OES Testing of a Certified Artificial Saltwater Standard By Rich Ross and Dr. Chris Maupin At MACNA 25 in Denver, the potential for the new

reefs.com

Do you rely on ICP tests from time-to-time? Have they helped you turn your tank around?

 

[Terry Martin]

I do a triton test every three to four months as I use cheap salt and does trace elements which are impossible to test well with kits. The tests definitely register changes in my dosing regime. Whether they are fully accurate or not, I have no idea though I think so or wouldn't waste the money. It's also just nice to make sure you don't have some source of heavy metal poisoning and catch it ahead of time. I wish they were more affordable so I could do them monthly.

 

[BiGGiePauls33]

I use ATI icp every 6 weeks. So far so good for the method that I follow.

 

[dz6t]

It depends on your system to see if ICP test works for you or not.
There are several things to consider:
1. How easy to do a large water change:
For small systems below 50 gallon, it is easy and very inexpensive to do a large water change. A bucket of 160gallon Reefcrystal is on par with an ICP test.

2. The best solution upon finding elevated levels of heavy metal via ICP test is large water change and run activated carbon. If that is the case, while waiting for the test results to come back, you may already miss the window of opportunity to fix the problem via large water change. Do a large water change if you see something wrong with the system immediately may be the best solution.

3. For large systems, run ICP test once a month does provide some peace of mind.

if you can and are comfortable to do large % water change, I will say doing water change will provide better results.

 

[chadfish]

It depends on your system to see if ICP test works for you or not.
There are several things to consider:
1. How easy to do a large water change:
For small systems below 50 gallon, it is easy and very inexpensive to do a large water change. A bucket of 160gallon Reefcrystal is on par with an ICP test.

2. The best solution upon finding elevated levels of heavy metal via ICP test is large water change and run activated carbon. If that is the case, while waiting for the test results to come back, you may already miss the window of opportunity to fix the problem via large water change. Do a large water change if you see something wrong with the system immediately may be the best solution.

3. For large systems, run ICP test once a month does provide some peace of mind.

if you can and are comfortable to do large % water change, I will say doing water change will provide better results.

Yeah, large water change has been my approach so far. I can’t change all 60 gal at once, so performing a series of 20% WC one each day. So far I’m up to 4. I think that’s about 40% the concentration of whatever my issue is. 0.8^4 =~0.41 so I’m at 41% of the original concentration of contaminant(s)

 

[dz6t]

Just for fun, there are several points to consider,

1. Well before ICP test become available for hobbyists, back in early 2000s, scientific community already knew that the complex nature of seawater prevented an ICP scan from providing an accurate view of metal content of seawater (Harker, 2004)

2. Contaminants are only toxic if they are incorporated into an organism’s tissues. (Hook & Fisher 2000)
To have any effect on coral or fish, good and bad, a metal must be in a form that can be absorbed into the tissue of the organism. Normally it need to be modified with organic compounds to be able to do anything, such as copper medication for saltwater fish.

3. The total concentration of a metal in the sea water is not a good predictor of how toxic it is. (Meyer, 2002)

4. An element exists in sea water does not mean it has any effect, good or bad, for coral. Actually many elements are simply there in the sea water as part of the earth system, they do absolutely nothing to coral.
I like to compare it to this scenario:
Imagine you got kidnapped by aliens, they tossed a rock in your cage thinking the rock must benefit your health (like a trace element), because they found rock in your natural habitat, aka your yard.

 

[N_E_M_O]

Yeah, large water change has been my approach so far. I can’t change all 60 gal at once, so performing a series of 20% WC one each day. So far I’m up to 4. I think that’s about 40% the concentration of whatever my issue is. 0.8^4 =~0.41 so I’m at 41% of the original concentration of contaminant(s)

Unfortunately it doesn't work that way in a recirculating closed system. Even if you changed all that water at once, most likely that percentage is still way off.
Example
Say you have a 100g tank, with 100ppm of nitrate. If you change 50 gallons of water, it will not automatically bring you to 50ppm, more likely 70-80ppm. Then in 2 days you could be back at 100ppm.
It never works as exact math with water changes unfortunately.
So large changes (50%+) and running carbon and other absorbing medias are the best bet when somethings wrong.

But personally I like ICP tests, as they gove us results for things we could never test for, let alone accurately. And if done regularly they can provide a good view as to trends in iyr tanks, and often warn of pending situations.

 

[chadfish]

Unfortunately it doesn't work that way in a recirculating closed system. Even if you changed all that water at once, most likely that percentage is still way off.
Example
Say you have a 100g tank, with 100ppm of nitrate. If you change 50 gallons of water, it will not automatically bring you to 50ppm, more likely 70-80ppm. Then in 2 days you could be back at 100ppm.
It never works as exact math with water changes unfortunately.
So large changes (50%+) and running carbon and other absorbing medias are the best bet when somethings wrong.

But personally I like ICP tests, as they gove us results for things we could never test for, let alone accurately. And if done regularly they can provide a good view as to trends in iyr tanks, and often warn of pending situations.

The only way your math is true is because it’s not a pure closed system, it’s an open system for nitrate: I keep feeding fish and they keep excreting ammonia. But for contaminants that don’t change much over time - say copper or arsenic or whatever - it’s certainly true. If I have any volume of water with a certain concentration and I remove and replace half the water I just diluted by 50% and I will have 50% of the contaminant. If I continue to do this, I reduce the concentration by half each time.

 

[N_E_M_O]

The only way your math is true is because it’s not a pure closed system, it’s an open system for nitrate: I keep feeding fish and they keep excreting ammonia. But for contaminants that don’t change much over time - say copper or arsenic or whatever - it’s certainly true. If I have any volume of water with a certain concentration and I remove and replace half the water I just diluted by 50% and I will have 50% of the contaminant. If I continue to do this, I reduce the concentration by half each time.

Not true
In our tanks there are tons of areas where contaminants like copper, arsenic, phosphate, manganese, ext. will be trapped and can slowly leach out, like sand beds, live rock, filtration media, ect. So your math just does not work in a reef tank situation. A bucket of water with "x" amount of a certain thing, sure.
Trust me I know from plenty of personal experience. Tried your math method hundreds of times in the last 30 years and unfortunately it never works that way.
Again the best approach is several 50%+ water changes and running absorbtion media.

 

[Zirky]

By absorbtion media do you mean carbon and gfo?

 

[N_E_M_O]

By absorbtion media do you mean carbon and gfo?

That is a couple types, but not just those,
yes any media like that, that will absorb a toxin, as there are many