Hanna Checker - Nitrate HI782

RaymondL · Dec 12, 2022

Ok, I went to use for the first time the Hanna Nitrate HR checker - HI782, and at first, I got a reading of 0.0ppm. I don't think that was correct, so I went to use a Salisfert Nitrate kit, and followed by an API - both of these readings from these kits showed a reading of 5ppm. or so.

I went back to try the Hanna test: got 0.6ppm. So I did another test and it came back at 1.9ppm.

Thoughts?
Thanks

HankstankXXL750 · Dec 12, 2022

I use and have no problems that I know of. Maybe one or two tests in a year that I questioned but figured I erred in getting the powder in right.
I also saw something somewhere that they wiped the vial with a microfiber cloth before both readings sample and test.

As I’m typing this another thought. When putting in for the test, you have to press and hold button until 7 minute timer starts. If you just press and release it will read the vial before it fully reacts. The sample darkens during the 7 minute wait.

RaymondL · Dec 12, 2022

HankstankXXXL750 said:
I use and have no problems that I know of. Maybe one or two tests in a year that I questioned but figured I erred in getting the powder in right.
I also saw something somewhere that they wiped the vial with a microfiber cloth before both readings sample and test.

As I’m typing this another thought. When putting in for the test, you have to press and hold button until 7 minute timer starts. If you just press and release it will read the vial before it fully reacts. The sample darkens during the 7 minute wait.

I am indeed wiping down the vial with a microfiber cloth and doing an exam of it to ensure no fingerprints, markings or air bubbles in the vial. Correct, I press and hold the button until I see the 7:00 timer and the countdown begins for the reading.

HankstankXXL750 · Dec 12, 2022

RaymondL said:
I am indeed wiping down the vial with a microfiber cloth and doing an exam of it to ensure no fingerprints, markings or air bubbles in the vial. Correct, I press and hold the button until I see the 7:00 timer and the countdown begins for the reading.

I would contact Hanna, I test 5-6 tanks weekly with this and ULR phosphate and believe they are accurate. I also believe that from other posts, Hanna is good at customer service and will be able to answer your question, or replace you unit.

d2mini · Dec 12, 2022

And just to add to above, make sure you are getting all the powder into the vial, and mixing vigorously for 2 mins.

Then ya, I would contact Hanna about it.
This is one of the top rated Hanna checkers. Should be pretty accurate.

HankstankXXL750 · Dec 12, 2022

d2mini said:
And just to add to above, make sure you are getting all the powder into the vial, and mixing vigorously for 2 mins.

Then ya, I would contact Hanna about it.
This is one of the top rated Hanna checkers. Should be pretty accurate.

After getting the ULR phosphate tester I have started to hold the reagent packet by the corner that you cut around before I start and flick it with my finger on the opposite corner. Then cut and push in from each corner to create a little slide for the reagent to slide down.

RaymondL · Dec 12, 2022

d2mini said:
And just to add to above, make sure you are getting all the powder into the vial, and mixing vigorously for 2 mins.

Then ya, I would contact Hanna about it.
This is one of the top rated Hanna checkers. Should be pretty accurate.

Thanks - yup, I've ensure all powder is in the vial - I tried to do everything as best I can, but the fact that I"m getting 3 different results is disappointing. I suppose I can contact the LFS that I bought it from and see what they say - if I can do an exchange that'll be better than doing the warranty replacement.

taricha · Dec 12, 2022

two issues.
1) hanna HR NO3 packets: some have found that the packets were duds, with the suggestion that they aim for a low amount of Zinc, to keep the color at high nitrate (75ppm) from being off-the-charts - and if they undershoot the zinc - it might falsely generate a zero. Some have found an entire pack that read zeros incorrectly. (I've never had one of the hanna packets do that, but others have.)

2) uncertainty: if your actual value of the NO3 in your water was say 2ppm, then the hanna tests and the eyeballing of API and Salifert color might all be giving you the same answer within their combined uncertainty.

RaymondL · Dec 12, 2022

Well, this is interesting - I decided to do yet another test, and one thing I noticed right off the bat is that when shaking the vial with the powder for the 2 minutes - the color is much different than the initial 3 trials - so now on the table is the factor of timing of the test. I did the initial tests 3 hours ago - is it possible that Nitrates in my tank are changing so much by the minute, hour to give a different result?

I know dKH can change during the course of a day, but Nitrates too?

RaymondL · Dec 12, 2022

taricha said:
two issues.
1) hanna HR NO3 packets: some have found that the packets were duds, with the suggestion that they aim for a low amount of Zinc, to keep the color at high nitrate (75ppm) from being off-the-charts - and if they undershoot the zinc - it might falsely generate a zero. Some have found an entire pack that read zeros incorrectly. (I've never had one of the hanna packets do that, but others have.)

2) uncertainty: if your actual value of the NO3 in your water was say 2ppm, then the hanna tests and the eyeballing of API and Salifert color might all be giving you the same answer within their combined uncertainty.

RaymondL · Dec 12, 2022

Ok, I took a step back to get the facts on what's happening here.

I did a water change this morning, and after I filled up the tank again, I did a Nitrate test, which read 0.0PPM - The reading the day before was at 18ppm.

I didn't believe that the water change of 30% did that much to Nitrates, so I tested again around 10 minutes later, which gave a result of 0.16PPM

Approximately 15 minutes later, I did the test again, and it read 1.9PPM

3.5 hours later, I did the test again and now it's showing at 12.9PPM - as my previous post, when adding the powder, I noticed that the color was no longer as clear as the previous tests - it started to show more a prominent orange.

So that eludes to the next point - does Nitrates change that often in a tank such as that I experienced? If so, then perhaps there is nothing wrong with the Hanna checker.

HankstankXXL750 · Dec 12, 2022

RaymondL said:
Ok, I took a step back to get the facts on what's happening here.

I did a water change this morning, and after I filled up the tank again, I did a Nitrate test, which read 0.0PPM - The reading the day before was at 18ppm.

I didn't believe that the water change of 30% did that much to Nitrates, so I tested again around 10 minutes later, which gave a result of 0.16PPM

Approximately 15 minutes later, I did the test again, and it read 1.9PPM

3.5 hours later, I did the test again and now it's showing at 12.9PPM - as my previous post, when adding the powder, I noticed that the color was no longer as clear as the previous tests - it started to show more a prominent orange.

So that eludes to the next point - does Nitrates change that often in a tank such as that I experienced? If so, then perhaps there is nothing wrong with the Hanna checker.

According to @Randy Holmes-Farley changing water should reduce nitrates by the percentage of the water change. However I always wait for at least an hour to retest anything after a water change to ensure that a good blend of new water and tank water. So if you did a water change you might have been getting bad reads until the tank blended.

RaymondL · Dec 12, 2022

HankstankXXXL750 said:
According to @Randy Holmes-Farley changing water should reduce nitrates by the percentage of the water change. However I always wait for at least an hour to retest anything after a water change to ensure that a good blend of new water and tank water. So if you did a water change you might have been getting bad reads until the tank blended.

Thanks - that's actually right on the money - just off by a 8% Nitrates did drop. I tested right after the water change not thinking that I should have let the water stabilize a bit before taking the reading. I"m assuming that my last reading at 3.5 hours after the water change is the 'actual' reading. I already 'wasted' 5 packets of the reagent already, so not sure if I want to do another test a few hours from now.

HankstankXXL750 · Dec 12, 2022

I wouldn’t. I test weekly to see where I am at and determine water changes accordingly. Or any other adjustments I need to make. Since my phosphate bottomed out yesterday in one of my tanks I will be testing more frequently until I get this balanced. Unless making changes or some “event” in the tank, I don’t feel the need to test daily. Initially to determine how much the tank is producing or consuming to know if action is required, but once that is known and dosing or whatever is put in place to control it should stay relatively consistent.

dadnjesse · Dec 12, 2022

You didn't mention shaking the vile for 2 minutes until later in this thread, so make sure you do that. Also what is the expiration date of the packets in the kit. It could of sat a while in the store.

RaymondL · Dec 12, 2022

dadnjesse said:
You didn't mention shaking the vile for 2 minutes until later in this thread, so make sure you do that. Also what is the expiration date of the packets in the kit. It could of sat a while in the store.I

I did shake the vial for 2 minutes - correct. The expiration date is Aug 2026, so that's a long time away.

RaymondL · Dec 12, 2022

HankstankXXXL750 said:
I wouldn’t. I test weekly to see where I am at and determine water changes accordingly. Or any other adjustments I need to make. Since my phosphate bottomed out yesterday in one of my tanks I will be testing more frequently until I get this balanced. Unless making changes or some “event” in the tank, I don’t feel the need to test daily. Initially to determine how much the tank is producing or consuming to know if action is required, but once that is known and dosing or whatever is put in place to control it should stay relatively consistent.

Thanks - yeah, not wasting any more reagents on another test. I'm trying to establish a baseline as well and getting to know how the tank is 'behaving', so likely I'll have to test weekly as you.

Cheers