Hanna Checker Phosphate ULR accuracy

[fushi]

I clean every vial with rubbing alcohol and a microfiber cloth, if you’re dunking the whole vial in the tank, be careful about water sitting underneath the cap, the Hannah readers are not water resistant.

Also, I found the biggest discrepancy to be little micro bubbles inside the vile, after my two minutes of shaking I slowly rock the bottle back-and-forth to clear up any bubbles inside.

Would you take a look at Shirak’s comment? He made a comment about the .9 would have been a dark blue. It was in fact not blue when I pulled it out. Would that be a problem with the checker then?

I don’t ever remember having a result as highest .9, but the color gets darker the higher the reading, so if you’re getting a high reading and a clear vial that would indicate something blocking the sensor or a bad checker.

If the checker is used and new reagents, don’t fix the problem, it might make sense to try to take it apart and clean it.

You can also have issues with defects in the glass vial, so maybe something to take a close look at too.

 

[aus1230]

I don’t ever remember having a result as highest .9, but the color gets darker the higher the reading, so if you’re getting a high reading and a clear vial that would indicate something blocking the sensor or a bad checker.

If the checker is used and new reagents, don’t fix the problem, it might make sense to try to take it apart and clean it.

You can also have issues with defects in the glass vial, so maybe something to take a close look at too.

Just out of curiosity I went ahead and ran another three sets of tests. I made notice to inspect all of the glass vials and rinse my syringe with RODI between each test. The new test was as follows:
1. 0.06
2. 0.04
3. 0.02

 

[Shirak]

Just out of curiosity I went ahead and ran another three sets of tests. I made notice to inspect all of the glass vials and rinse my syringe with RODI between each test. The new test was as follows:
1. 0.06
2. 0.04
3. 0.02

That seems within typical results if it was the faintest blue it would be around .04ppm and the margin of error could give you between .06 and .02.

Regarding your previous comment that they were all very clear then something odd with the .2 and .9 ppm. Could be the reagents but unlikely. Do you have any phosphate on hand? You can add a tiny bit after running a test to the vial and see if it darkens.

I would stick with one vial and orient it in the same direction each time. That should eliminate any variance in the glass. I have seen some vials that were not clear glass and others that looked to be different thicknesses in the wall as you turn the vial. They are cheap glass...

 

[aus1230]

That seems within typical results if it was the faintest blue it would be around .04ppm and the margin of error could give you between .06 and .02.

Regarding your previous comment that they were all very clear then something odd with the .2 and .9 ppm. Could be the reagents but unlikely. Do you have any phosphate on hand? You can add a tiny bit after running a test to the vial and see if it darkens.

I would stick with one vial and orient it in the same direction each time. That should eliminate any variance in the glass. I have seen some vials that were not clear glass and others that looked to be different thicknesses in the wall as you turn the vial. They are cheap glass...

Yeah placing an order for some glass and some more reagents today.

 

[aus1230]

Yeah placing an order for some glass and some more reagents today.

That seems within typical results if it was the faintest blue it would be around .04ppm and the margin of error could give you between .06 and .02.

Regarding your previous comment that they were all very clear then something odd with the .2 and .9 ppm. Could be the reagents but unlikely. Do you have any phosphate on hand? You can add a tiny bit after running a test to the vial and see if it darkens.

I would stick with one vial and orient it in the same direction each time. That should eliminate any variance in the glass. I have seen some vials that were not clear glass and others that looked to be different thicknesses in the wall as you turn the vial. They are cheap glass...

Was going to order some more reagents and vials but by the time I put them in my cart the new checker with vials and some reagents was only like 15 dollars more since it's currently on sale on bulk reef supply

 

[bubbgee]

I end up buying new sensors. These colorimeters seem to last only 2-3 years at best. Both my phosphate and nitrate ones are throwing weird numbers that I ended up getting new ones.

 

[Shirak]

I end up buying new sensors. These colorimeters seem to last only 2-3 years at best. Both my phosphate and nitrate ones are throwing weird numbers that I ended up getting new ones.

Huh weird. Mine have been going fine for 5+ years. I am at the point now that I can look at the color and get a pretty good idea if the number on the checker is about where it should be LOL

 

[fushi]

Huh weird. Mine have been going fine for 5+ years. I am at the point now that I can look at the color and get a pretty good idea if the number on the checker is about where it should be LOL

same lol

 

[Tangdora]

If I’m being honest none of them had any color when finished. Would that mean the reagent then?

How old is the battery. Did you try swapping it.

 

[spicymikey]

Not exactly what to think here or maybe this is normal so I apologize in advance. I know these checkers might have discrepancies but is this just a small one or a big difference?
Initial reading was 0.03
2nd reading was 0.2
3rd reading was 0.90 which seamed like a crazy discrepancy so I decided to test again
The 4th reading was 0
Is that normal to have those variations after doing back to back tests with new packets within minutes of each other?

The packets expire this December if that's worth anything?

No that is not normal or even explainable assuming you are:
- Testing at the same time of day and your daily routine is the same regarding feeding
- You are careful to get "all" of the reagent out of the packet. Realize there will always be dust left clinging to the packet.
- The tester is not broken. Has it EVER worked reliably?

These testers are very accurate and consistent. If this batch of reagent is that old and expiring in a few months then maybe that is the answer. Easy way to find out is to get a fresh box.

Also, try testing the same sample twice in a row. If you get different results then maybe its the checker itself.

Good luck

 

[disaster999]

Been dealing with wild readings with my hanna phosphorus ULR reader also. I have 2 vials, 1 with tank water and 1 with tank + reagent. I mix the vial for about 3 mins as suggested or until I dont see anymore powder floating around and start the test. I follow the prompt on the checker, turn on the checker, put C1, click, wait for it to tell me to put C2, then click and wait for the reading. I do this about 3-5 times depending on the readings I get. My latest reading yields:

1st reading: 30
2nd reading: 9
3rd reading: 0
4th reading: 36
5th reading: 32

Knowing the 9 and 0 reading are properly outliers, I just discard those reading and average the 30, 32, 36 reading and assume this is the true reading for my tank.Some of the times I will get wild readings like 20, 11, 9, 0, and Im standing here scratching my head like...so is my tank at 20 or 0? Ive done several ICP test and it seems like the reading Im getting with the Hanna is consistantly higher than what the ICP test results shows.

Reagents are not expired I had this checker for years and have gone through several 25 packet boxes of reagents, not one time I can consistent readings ±5 ppb or ±5% of reading as specified. I just kind of live with it knowing it gives me a well enough ball park number.

 

[gbroadbridge]

Been dealing with wild readings with my hanna phosphorus ULR reader also. I have 2 vials, 1 with tank water and 1 with tank + reagent. I mix the vial for about 3 mins as suggested or until I dont see anymore powder floating around and start the test. I follow the prompt on the checker, turn on the checker, put C1, click, wait for it to tell me to put C2, then click and wait for the reading. I do this about 3-5 times depending on the readings I get. My latest reading yields:

1st reading: 30
2nd reading: 9
3rd reading: 0
4th reading: 36
5th reading: 32

Knowing the 9 and 0 reading are properly outliers, I just discard those reading and average the 30, 32, 36 reading and assume this is the true reading for my tank.Some of the times I will get wild readings like 20, 11, 9, 0, and Im standing here scratching my head like...so is my tank at 20 or 0? Ive done several ICP test and it seems like the reading Im getting with the Hanna is consistantly higher than what the ICP test results shows.

Reagents are not expired I had this checker for years and have gone through several 25 packet boxes of reagents, not one time I can consistent readings ±5 ppb or ±5% of reading as specified. I just kind of live with it knowing it gives me a well enough ball park number.

You should follow the instructions as shown in the OFFICIAL video below.
Do NOT use two cuvettes for the test . The second is a spare for when the first one is broken or discoloured.

 

[disaster999]

You should follow the instructions as shown in the OFFICIAL video below.
Do NOT use two cuvettes for the test . The second is a spare for when the first one is broken or discoloured.

You are missing the point here. Im talking about the wild discrepancy and variation between tests, not accuracy. How can I ensure each single test result is remotely accurate when the unit itself throws a curve ball at you from time to time?

 

[gbroadbridge]

You are missing the point here. Im talking about the wild discrepancy and variation between tests, not accuracy. How can I ensure each single test result is remotely accurate when the unit itself throws a curve ball at you from time to time?

I'm not missing the point.

Unless the tester is faulty, the only way for dramatic variations from samples taken at the same time is incorrect procedure.

You stated that you are using two cuvettes, one for the blank and another with the reagent.
That is incorrect procedure which will result in incorrect results.

I've been using that tester for almost 5 years - results from the same sample are always within +/- 0.02 ppm in my experience, which is within spec.

 

[Shirak]

One cuvette! Mark it so you can orient it in the same direction as well. Clean it orient it and get C1 reading. (Turn on and wait for dashes to go away, Insert and press button) Dump in reagents and shake gently for 2 minutes. Gentle swirl after to dislodge any micro bubbles etc. Orient and put back in checker and hold button for 3min countdown. That's all I do and it's worked great for years and years. After testing I rinse and shake with RODI several times, fill with RODI and cap.

Also make sure you are closing the tester cover all the way since it is a light based system.

 

[TankYouVeryMuch]

There’s most likely a contaminant (dirt) on the cuvette or between the light and the sensor. Maybe try cleaning the cuvette with some citric acid or vinegar. If it was a problem with the light/sensor itself, I’d expect it to be consistently high or low.

Been dealing with wild readings with my hanna phosphorus ULR reader also. I have 2 vials, 1 with tank water and 1 with tank + reagent. I mix the vial for about 3 mins as suggested or until I dont see anymore powder floating around and start the test. I follow the prompt on the checker, turn on the checker, put C1, click, wait for it to tell me to put C2, then click and wait for the reading. I do this about 3-5 times depending on the readings I get. My latest reading yields:

1st reading: 30
2nd reading: 9
3rd reading: 0
4th reading: 36
5th reading: 32

Knowing the 9 and 0 reading are properly outliers, I just discard those reading and average the 30, 32, 36 reading and assume this is the true reading for my tank.Some of the times I will get wild readings like 20, 11, 9, 0, and Im standing here scratching my head like...so is my tank at 20 or 0? Ive done several ICP test and it seems like the reading Im getting with the Hanna is consistantly higher than what the ICP test results shows.

Reagents are not expired I had this checker for years and have gone through several 25 packet boxes of reagents, not one time I can consistent readings ±5 ppb or ±5% of reading as specified. I just kind of live with it knowing it gives me a well enough ball park number.

There’s most likely a contaminant (dirt) on the cuvette or between the light and the sensor. Maybe try cleaning the cuvette with some citric acid or vinegar. If it was a problem with the light/sensor itself, I’d expect it to be consistently high or low.

 

[Lonzo365]

Not exactly what to think here or maybe this is normal so I apologize in advance. I know these checkers might have discrepancies but is this just a small one or a big difference?
Initial reading was 0.03
2nd reading was 0.2
3rd reading was 0.90 which seamed like a crazy discrepancy so I decided to test again
The 4th reading was 0
Is that normal to have those variations after doing back to back tests with new packets within minutes of each other?

The packets expire this December if that's worth anything?

I am having the same trouble. Hanna giving high numbers and Salifert test showing 0. Did you ever find out a resolution?

 

[Shirak]

I am having the same trouble. Hanna giving high numbers and Salifert test showing 0. Did you ever find out a resolution?

What does the color of your sample look like? Should be pretty easy to tell if one is off. Very low phosphate should be barely perceptible blue color on the test sample. And I mean barely! The faintest of faint. And a 0 would be no color change at all. When you say high with the Hanna, how high?

 

[Lonzo365]

What does the color of your sample look like? Should be pretty easy to tell if one is off. Very low phosphate should be barely perceptible blue color on the test sample. And I mean barely! The faintest of faint. And a 0 would be no color change at all. When you say high with the Hanna, how high?

The color was very light the slightest of blue if any. first reading was .87, second with Hanna was .18. Salifert indicated 0. Trying to figure out what I am doing wrong with Hanna test. I set my timer for 2 minutes and shake gently per instructions. Wiping tubes off during calibration and test. Just washed tubes prior to use and always rinse out with RODI after testing.

 

[bandando]

I have noticed anomalies in the readings me too.
Many times, after dissolving the reagent in the vial, black-colored residues remain.
When these are present, the reading is clearly incorrect.
By now, whenever I see them, I throw the sample away and start over.

The problem is that, even with brand-new reagents from different lots and packages, this happens to me almost one out of every two times.
I have written to Hanna Italy (where I live) and Hanna USA, but I have never received a reply.