This ATI icp test cant be right

[Marc2952]

I have always done icp tests with ATI, i usually do them every 3 months but this last result that came got me scratching my head. How can it be possible that it shows alk so much higher then what my hanna test kit shows? I test alk daily and my alk usually stays betweem 8.1-8.6. I even tested my freshly mix saltwater that i do with tropic marin pro and alk usually reads 7.1 which seems to be correct from the hannas side. This are the reults from the icp test. @Randy Holmes-Farley any thoughts? The day i took the water sample i did a test and saved it just to compare it to the icp test and had an alk reading of 8.4 from my hanna.

 

[X-37B]

I would get another reading from say a salifert test kit.
In use Hanna and have salifert and elos as a cross reference.
If all 3 are close, which they always are for me, then the ati must be off.

 

[Marc2952]

I would get another reading from say a salifert test kit.
In use Hanna and have salifert and elos as a cross reference.
If all 3 are close, which they always are for me, then the ati must be off.

Gonna get a salifert test kit and gonna let my LFS guy test for me aswell just to be sure. Its such a difference that its alarming to me since i have lost 2 acros and a monti this month but i thought it was due to my nutrients bottoming out due to going fallow.

 

[User1]

I have always done icp tests with ATI, i usually do them every 3 months but this last result that came got me scratching my head. How can it be possible that it shows alk so much higher then what my hanna test kit shows? I test alk daily and my alk usually stays betweem 8.1-8.6. I even tested my freshly mix saltwater that i do with tropic marin pro and alk usually reads 7.1 which seems to be correct from the hannas side. This are the reults from the icp test. @Randy Holmes-Farley any thoughts? The day i took the water sample i did a test and saved it just to compare it to the icp test and had an alk reading of 8.4 from my hanna.

If you haven't send ATI a message and ask what they think. You can send in your manual test results as well. Of course it would help if you ran the tests using water sampled at the same time you drew ATI's vials.

That is what I do actually. Just before the Tridents noon tests I grab a pitcher of water from the tank, fill up ATI's tubes then run through Hanna ALK and Phosphate tests and Nyos for Nitrates. Dump remaining water back in the tank and send off the ATI ICP test. In 7 or so days I can now compare ATI's results to the three tests I ran manually to the Tridents and usually everything is grand.

Within their respected margin of error room. One time ATI's salinity was lower, much lower than mine so I sent them a message as my manual tests looked good. They suggested using calibration or a reference fluid. The chemistry forum also suggested this. Low and behold ATI's results are correct and I had low salinity.

Anyway not saying that is the case but I found sending a quick email worked and they replied. Doesn't answer your question but figured I'd offer the email bit if you haven't already done so. Their support and response is great at least as far as I've used it.

 

[Rickyrooz]

I wouldn't worry about the ICP reading for alkalinity. I believe Randy said in the past that the ICP machine cannot accurately detect carbonate hardness. The companies that are offering alkalinity test results along with the ICP test results are performing the manual titration.

 

[LeftyReefer]

I've noticed my Hanna ALK checker can give me wonky results when I'm nearing the bottom of each reagent bottle...

if your current bottle of reagent is very low, you might want to crack open a new bottle and check it again.

 

[tautog83]

Yea I thought I remembering reading that icp results for alk arent usually very accurate

 

[Marc2952]

I've noticed my Hanna ALK checker can give me wonky results when I'm nearing the bottom of each reagent bottle...

if your current bottle of reagent is very low, you might want to crack open a new bottle and check it again.

I actually just changed the reagent bottle 2 days ago and was only off my 0.2 dkh which is normal since the reagent bottles are usually never identical.

 

[Marc2952]

Yea I thought I remembering reading that icp results for alk arent usually very accurate

Ok so i will test with a salifert and my LFS. I just messaged ATI aswell to see what they think, ive done alot of icp tests with them and this is a first, and the fact that i checked my freshly mixed saltwater with tropic marin pro and came out right on the dot makes me think that infact its a mistake on their part but you can never be sure i guess.

 

[Marc2952]

I wouldn't worry about the ICP reading for alkalinity. I believe Randy said in the past that the ICP machine cannot accurately detect carbonate hardness. The companies that are offering alkalinity test results along with the ICP test results are performing the manual titration.

Oh thats a bummer i always thought their alk tests where more accurate then ours.

 

[92Miata]

I've noticed my Hanna ALK checker can give me wonky results when I'm nearing the bottom of each reagent bottle...

if your current bottle of reagent is very low, you might want to crack open a new bottle and check it again.

This.

My Checker is only good for about 15 tests per bottle (instead of the 25 hanna says, or the 30 or so that there's actually enough reagent in the bottle to do) and then it starts drifting down. 15 tests is about -.2. 20 is about -.5, and by 25 I'm a full dkh low.


After that it drifts reaaally low.

I've never seen it be 4dkh low, but I've seen it read 6 when the tank is 8.5

 

[Randy Holmes-Farley]

I wouldn't worry about the ICP reading for alkalinity. I believe Randy said in the past that the ICP machine cannot accurately detect carbonate hardness. The companies that are offering alkalinity test results along with the ICP test results are performing the manual titration.

It's not that the numbers are inaccurate., it is that ICP cannot in any way measure alkalinity.

Companies that provide this result are doing a titration, just like a test kit.

 

[Marc2952]

It's not that the numbers are inaccurate., it is that ICP cannot in any way measure alkalinity.

Companies that provide this result are doing a titration, just like a test kit.

So how do i know which one is correct? Test from different test kits? I tested my tropic marin saltmix and it read 7.1 which seems to be about right for those saltmix.

 

[Marc2952]

This.

My Checker is only good for about 15 tests per bottle (instead of the 25 hanna says, or the 30 or so that there's actually enough reagent in the bottle to do) and then it starts drifting down. 15 tests is about -.2. 20 is about -.5, and by 25 I'm a full dkh low.


After that it drifts reaaally low.

I've never seen it be 4dkh low, but I've seen it read 6 when the tank is 8.5

Oh wow so i gotta throw out the bottle before it gets to the last one. I also heard any scratch in the crystal vial can affect the test aswell. This is stressful lol

 

[X-37B]

I use the hanna solution to the last drop, lol.
I test every morning.
My vial has a few scratches and is over 3 years old.
I used a new one and the reading was within .1.
I have got .2 difference when going to a new bottle at times.
*Verified with salifert*
I do not think a varience of .2 is even noticed in a tank as most have a bigger swing.

 

[Marc2952]

I use the hanna solution to the last drop, lol.
I test every morning.
My vial has a few scratches and is over 3 years old.
I used a new one and the reading was within .1.
I have got .2 difference when going to a new bottle at times.
*Verified with salifert*
I do not think a varience of .2 is even noticed in a tank as most have a bigger swing.

So something must be way off then a difference of 4dkh between my hanna and ATI is huge.

 

[Marc2952]

also my hanna phosphate 713 was showing 0.00 and the ati showed 0.05 but that doesnt me nearly as much as the alk.

 

[X-37B]

also my hanna phosphate 713 was showing 0.00 and the ati showed 0.05 but that doesnt me nearly as much as the alk.

I have both hanna po4's.
Get the ulr.
The 713 has a .04 tolerance so 0 can be .04.
The ATI test was off most likely.
Just get the salifert like you are planning and test side by side with the hanna for alk.

 

[User1]

It's not that the numbers are inaccurate., it is that ICP cannot in any way measure alkalinity.

Companies that provide this result are doing a titration, just like a test kit.

I wonder what they use test kit wise, and how consistent they are. Out of curiosity of course.

 

[DeeBee]

I had the exact same issue on my last ATI ICP test. Alkalinity was over 2 points higher dKH than what I get on my Hanna colorimeter egg tester. I plan to get a Salifert test to double check, but my guess is that it's on the ATI side.

To Randy's point, they aren't getting the Alk values via ICP but a separate test.