Hanna Nitrate 18 vs ICP 45

[Ironfish]

Hi,

Ive been using several Hanna Checkers for years, mainly bc of its ease of use and accuracy.
But over a month ago I got my ICP tests results back and the Nitrate level was VERY different to my Hanna.
Hanna Nitrate HR read 22.8
ATI ICP read 54

I assumed ICP was off bc my tank has always be around 20-25.

So a couple weeks ago I sent a new sample and readings just got back.
Hanna: 18.7
ICP: 45.

I ended up emailing ATI and they explained to me that most likely the wrong numbers are coming from my Hanna checker.

I got new reagents just in case and re tested. Same results.

I understand there's no way or need to calibrate.
The test is pretty straightforward so Im not sure the issue.

Has anyone experience this? Or similar?
Is there a way to fix it?

Thanks!

 

[Randy Holmes-Farley Verified Community Expert]

I ended up emailing ATI and they explained to me that most likely the wrong numbers are coming from my Hanna checker.

I got new reagents just in case and re tested. Same results.

I understand there's no way or need to calibrate.
The test is pretty straightforward so Im not sure the issue.

Has anyone experience this? Or similar?
Is there a way to fix it?

Thanks!

Of course they said that. lol

It may be true, it may be that degradation took place in shipping and both are accurate, it may be the ATI test was off, or maybe even both are off. lol

Luckily, every value you mentioned is within my target range. :)

 

[KC2020]

Spend $20 bucks on a Salifert NO3 test kit. You'll eliminate the shipping conditions variable, which has a high potential for affecting results, and you're using a kit that's known for consistency and accuracy.

 

[exnisstech]

This is my ATI results for 2 RODI samples pulled from the same container.

 

[Gsponi]

I did an ICP 1week ago. Also ATI. And i tested at the dame time .
PO4 Hanna checker 0.09 i dose ATI P
and salinity 1.023 at 25°C with an aerometer, so its exact i think.

At the ICP it says Po4 n.n and totale phospat also n.n.

And salinity at 32.9 psu

I think its because i live in seitzerland and until i get the results from germany its sometimes 10 days. so probably its the transport . Because my corals show me when my po4 ist near 0

 

[P500]

Hi,

Ive been using several Hanna Checkers for years, mainly bc of its ease of use and accuracy.
But over a month ago I got my ICP tests results back and the Nitrate level was VERY different to my Hanna.
Hanna Nitrate HR read 22.8
ATI ICP read 54

I assumed ICP was off bc my tank has always be around 20-25.

So a couple weeks ago I sent a new sample and readings just got back.
Hanna: 18.7
ICP: 45.

I ended up emailing ATI and they explained to me that most likely the wrong numbers are coming from my Hanna checker.

I got new reagents just in case and re tested. Same results.

I understand there's no way or need to calibrate.
The test is pretty straightforward so Im not sure the issue.

Has anyone experience this? Or similar?
Is there a way to fix it?

Thanks!

Strange, I have exacly the same. Now for the second time. Also with ATI ICP. My Hanna reads NO3 of 21.9 and the last ATI ms ICP gives me an NO3 of 66.19...

 

[Dan_P]

Of course they said that. lol

It may be true, it may be that degradation took place in shipping and both are accurate, it may be the ATI test was off, or maybe even both are off. lol

Luckily, every value you mentioned is within my target range. :)

I can’t think of a likely mechanism to increase nitrate by that much by degradation.

One could invoke a bad batch of reagent. A plausible error, although how likely I don’t know, is user error. The two minute vigorous shaking in the Hanna HR nitrate test is important and insufficient shaking would result in a low reading. I have not tested this, but given the small amount of reducing agent, I suspect this vigorously shaken step might be the culprit.

 

[areefer01]

I can’t think of a likely mechanism to increase nitrate by that much by degradation.

One could invoke a bad batch of reagent. A plausible error, although how likely I don’t know, is user error. The two minute vigorous shaking in the Hanna HR nitrate test is important and insufficient shaking would result in a low reading. I have not tested this, but given the small amount of reducing agent, I suspect this vigorously shaken step might be the culprit.

Vigorously shaken. Is one important piece of the puzzle. Agreed. May even be THE most important.

I've run into a few other oddities during my several month of testing with the Trident NP. Lets see:

• Bad reagent pack. Expiration date good, reagents not consistent and way outside margin of error. Hanna replaced for free which was nice.
• Battery. Did not say battery was low but was getting inconsistent daily results, changed the battery, and results back to normal.
• Cuvette and cap. I was also using the Hanna phosphate checker and so I would keep them all together and randomly grab one to use. I would run a days test, throw it in excel, test again the next day, repeat. I would see nitrate results vary and the NP's consistent. The trends. Said ok, what is wrong, so used the same cuvette and cap and the numbers trended no spikes. Also the egg / lid actually snapped close which leads me to believe while they are all 10 ml there is a bit of play in the cuvette size or cap.
• Exercise, er, shake shake shake Senora shake your body line Harry Belafonte. Phosphate is more of a tumble and roll because the countdown in 3 minutes. Nitrate is 7 countdown, not the final countdown, but THE countdown so this is why I think hanna notes vigorous.

All things that I found while going through many, many, nitrate and phosphate reagent boxes. And even now I'll get some oddities when i do a battery of tests using the same pint of water sample that I use for all tests. Throw out the anomaly and we're good...

Test	Result
1	31.4
2	41.3
3	33.7
4	30
	34.10

 

[Dan_P]

Vigorously shaken. Is one important piece of the puzzle. Agreed. May even be THE most important.

I've run into a few other oddities during my several month of testing with the Trident NP. Lets see:

• Bad reagent pack. Expiration date good, reagents not consistent and way outside margin of error. Hanna replaced for free which was nice.
• Battery. Did not say battery was low but was getting inconsistent daily results, changed the battery, and results back to normal.
• Cuvette and cap. I was also using the Hanna phosphate checker and so I would keep them all together and randomly grab one to use. I would run a days test, throw it in excel, test again the next day, repeat. I would see nitrate results vary and the NP's consistent. The trends. Said ok, what is wrong, so used the same cuvette and cap and the numbers trended no spikes. Also the egg / lid actually snapped close which leads me to believe while they are all 10 ml there is a bit of play in the cuvette size or cap.
• Exercise, er, shake shake shake Senora shake your body line Harry Belafonte. Phosphate is more of a tumble and roll because the countdown in 3 minutes. Nitrate is 7 countdown, not the final countdown, but THE countdown so this is why I think hanna notes vigorous.

All things that I found while going through many, many, nitrate and phosphate reagent boxes. And even now I'll get some oddities when i do a battery of tests using the same pint of water sample that I use for all tests. Throw out the anomaly and we're good...

Test	Result
1	31.4
2	41.3
3	33.7
4	30
	34.10

Nice investigation and detailed report.

Makes me want to burn through a box of reagent testing the same water sample, varying shake time and vigor of the shaking.

 

[EnterName]

Vigorously shaken. Is one important piece of the puzzle. Agreed. May even be THE most important.

I've run into a few other oddities during my several month of testing with the Trident NP. Lets see:

• Bad reagent pack. Expiration date good, reagents not consistent and way outside margin of error. Hanna replaced for free which was nice.
• Battery. Did not say battery was low but was getting inconsistent daily results, changed the battery, and results back to normal.
• Cuvette and cap. I was also using the Hanna phosphate checker and so I would keep them all together and randomly grab one to use. I would run a days test, throw it in excel, test again the next day, repeat. I would see nitrate results vary and the NP's consistent. The trends. Said ok, what is wrong, so used the same cuvette and cap and the numbers trended no spikes. Also the egg / lid actually snapped close which leads me to believe while they are all 10 ml there is a bit of play in the cuvette size or cap.
• Exercise, er, shake shake shake Senora shake your body line Harry Belafonte. Phosphate is more of a tumble and roll because the countdown in 3 minutes. Nitrate is 7 countdown, not the final countdown, but THE countdown so this is why I think hanna notes vigorous.

All things that I found while going through many, many, nitrate and phosphate reagent boxes. And even now I'll get some oddities when i do a battery of tests using the same pint of water sample that I use for all tests. Throw out the anomaly and we're good...

Test	Result
1	31.4
2	41.3
3	33.7
4	30
	34.10

Nice investigation and detailed report.

Makes me want to burn through a box of reagent testing the same water sample, varying shake time and vigor of the shaking.

Don't hurt yourself

While not particularly odd (it's a different test after all), I think it's interesting that you need to shake the sample so much while the salifert test explicitly states to not shake and just gently swirl the vial.

 

[Dan_P]

Don't hurt yourself

While not particularly odd (it's a different test after all), I think it's interesting that you need to shake the sample so much while the salifert test explicitly states to not shake and just gently swirl the vial.

Salifert uses a soluble nitrate reducing reagent in its formulation and its identity seems to be a secret. Also, its reduction of nitrate to nitrite might not be as high as zinc or cadmium, though I have not experimentally confirmed this. Still on the to-do list.

 

[EnterName]

Salifert uses a soluble nitrate reducing reagent in its formulation and its identity seems to be a secret. Also, its reduction of nitrate to nitrite might not be as high as zinc or cadmium, though I have not experimentally confirmed this. Still on the to-do list.

Maybe there is something in their Safety Data Sheet...

They apparently are quite proud of the test not suffering from amine interference:

"The Salifert nitrate test does not suffer from such an amine interference. The very special ingredients allow a very fast and precise measurement.

The range spans from very low to a very high nitrate concentration (approx. 0.05 – 20 mg/L as Nitrate-Nitrogen or 0.2 – 100 mg/L as nitrate ion).

The kit can perform approx. 60 measurements."

 

[Dan_P]

Maybe there is something in their Safety Data Sheet...

They apparently are quite proud of the test not suffering from amine interference:

"The Salifert nitrate test does not suffer from such an amine interference. The very special ingredients allow a very fast and precise measurement.

The range spans from very low to a very high nitrate concentration (approx. 0.05 – 20 mg/L as Nitrate-Nitrogen or 0.2 – 100 mg/L as nitrate ion).

The kit can perform approx. 60 measurements."

I don’t recall finding anything useful.

On the speculation front, Sulfamic acid reduces nitrite to N2. Maybe there is a sulfur compound that reduces nitrate to nitrite.