Hannah phos checker timing

[Bpb]

I assumed the reading was most accurate at the 3 minute mark so I don’t mix any prior to starting the timer.

Super easy and fast. Single vial method

Rinse vial with tank water. Dump. Refill using the same syringe every time.
Cut open packet. Have the reagent all in the bottom and the corners opened and create a bend on the flat portions for easy pouring. Tap the bag to ensure all powder is at the bottom.

Put curvette in checker. Press for c1, When it says press for c2, I hold button to start timer

Immediately pour in reagent taking care not to spill any, quickly
Cap and begin inverting the curvette for about 2:30. Set upright and tap. Ensure there are no bubbles. By then the reagent is always fully dissolved.

Put in checker, read result when it pops up.

Easy peasy. If you don’t violently shake the vial you won’t get a ton of micro bubbles. The one big bubble going up and down is more than enough to mix the reagent.

 

[sghera64]

I assumed the reading was most accurate at the 3 minute mark so I don’t mix any prior to starting the timer.

Super easy and fast. Single vial method

Rinse vial with tank water. Dump. Refill using the same syringe every time.
Cut open packet. Have the reagent all in the bottom and the corners opened and create a bend on the flat portions for easy pouring. Tap the bag to ensure all powder is at the bottom.

Put curvette in checker. Press for c1, When it says press for c2, I hold button to start timer

Immediately pour in reagent taking care not to spill any, quickly
Cap and begin inverting the curvette for about 2:30. Set upright and tap. Ensure there are no bubbles. By then the reagent is always fully dissolved.

Put in checker, read result when it pops up.

Easy peasy. If you don’t violently shake the vial you won’t get a ton of micro bubbles. The one big bubble going up and down is more than enough to mix the reagent.

We had a long thread on R2R a while back. @MnFish1 ended up contacting Hanna. We learned that it is vital to result accuracy that the sample be taken as close to 5 min after reagent addition as possible.

 

[Pmj]

I assumed the reading was most accurate at the 3 minute mark so I don’t mix any prior to starting the timer.

Super easy and fast. Single vial method

Rinse vial with tank water. Dump. Refill using the same syringe every time.
Cut open packet. Have the reagent all in the bottom and the corners opened and create a bend on the flat portions for easy pouring. Tap the bag to ensure all powder is at the bottom.

Put curvette in checker. Press for c1, When it says press for c2, I hold button to start timer

Immediately pour in reagent taking care not to spill any, quickly
Cap and begin inverting the curvette for about 2:30. Set upright and tap. Ensure there are no bubbles. By then the reagent is always fully dissolved.

Put in checker, read result when it pops up.

Easy peasy. If you don’t violently shake the vial you won’t get a ton of micro bubbles. The one big bubble going up and down is more than enough to mix the reagent.

I do the same except put the reagent in first, as that can take a sec. put it in, press timer, shake 2 min, wait another minute for results.

 

[cracker]

I use a timer set for 2 mins 45 secsonds. You have 15 seconds to set the vial. It's usually well dissolved by then any way. I keep forgetting to hold the button until the timer to starts ! Then I have to do it all over again !
Any tips for this ?

 

[JMetaxas]

Mine shuts off after about 2:45. I learned this today. But, I always get the reagent packet ready to dump in the cuvette.

I mix for about 2 minutes then let it sit for about 30 seconds before hitting the button to start the 3:00 timer to get a reading.

 

[MnFish1]

We had a long thread on R2R a while back. @MnFish1 ended up contacting Hanna. We learned that it is vital to result accuracy that the sample be taken as close to 5 min after reagent addition as possible.

It is 'essential' according to Hanna that the results are read at 5 minutes. (according to their technical support department). When doing tests (especially for ultra low phosphorous) I'm surprised that so many people are not doing the test correctly - and may be basing decisions on incorrect results.

PS - the auto-shut off in the 'tech specs' on the hanna website is after 3 minutes of 'no use' and 2 minutes after displaying the reading.

 

[User1]

Ironically enough after reading this thread twice now I pulled out my Hanna checker and tried another test. I was about to launch it into low earth orbit out of frustration but knew the issue was me... Anyway thanks. I got it after reading this a couple times like I noted above and got back to back results of 0.25 which is what I expected more or less. 150 lbs of dry pukani in a recently cycled tank and 40 breeder consolidation. I was actually expecting it to be higher...

Anyway thanks for the thread. You all saved a Hanna checker today /flex

 

[PatW]

I turn on the unit and get the C1.

I add the sample to the vial. I wipe finger prints off the vial. I cut the sample packet. I have a funnel and have that ready.

I push the button. When I get C2, time is awasting!

I position the funnel. I dump the powder in. Put on the cap. I shake vigorously for a minute and that dissolves the powder. Then I very slowly move the bubble in the vial back and forth to remove any small bubbles. About 50 seconds, I wipe the vial clean of finger prints, insert it, close the lid and mash the button to start the 3 min count down.

 

[PedroYoung]

Holy malarki, is this not how to do it? I am confused.

 

[Crashjack]

I solved the issue by getting a different test kit. I might pull out the Hanna again some time if I really just want to torture myself for some reason.

 

[dede]

If I understand what you wrote, then you are analyzing the sample about 3 minutes after mixing the reagent into it. Is that right?

I start the clock as soon as the hanna checker shows the C2. So in the 3 min window I am removing the vial, adding the reagent and then shaking until about 15 seconds are left. When I see the 15 seconds I wipe down the vial and add to the checker. Then compress the black button on the checker until the clock starts.

The point of the 3 min timer for me is that the checker will turn off if I take too long. When I first started using the checker it was shutting off to soon, either for the test or I forgot to look for the result. I was reading a lot of post on this and one said you only really need to shake the vial after adding reagent for 2 minutes for an accurate result.

Another helpful hint I read somewhere for adding the reagent was to flick the reagent along the black lines to help product to fall to bottom, cut along lines, then open along those lines slowly and flick again so all reagent is in the bottom. Now holding the corners of each cut end slowly move them towards each other, like you were making the package talk "Ohhh." The reagent will poor out so much easier now with the rounded area. Before I was trying to scrape it out with a small knife and it was taking too long and too messy.

 

[Bpb]

Quite a difference. I mixed the vial for 2 minutes prior to starting the 3 minute timer to give it the full 5 minutes and I got a reading of 8 ppb versus 26 ppb previously only waiting the 3 minutes for resulting

 

[sghera64]

Quite a difference. I mixed the vial for 2 minutes prior to starting the 3 minute timer to give it the full 5 minutes and I got a reading of 8 ppb versus 26 ppb previously only waiting the 3 minutes for resulting

@dede The above is how you perform the method and why its done that way. By only allowing 3 minutes for the sample to react, you are getting an erroneous value.

 

[MnFish1]

I start the clock as soon as the hanna checker shows the C2. So in the 3 min window I am removing the vial, adding the reagent and then shaking until about 15 seconds are left. When I see the 15 seconds I wipe down the vial and add to the checker. Then compress the black button on the checker until the clock starts.

The point of the 3 min timer for me is that the checker will turn off if I take too long. When I first started using the checker it was shutting off to soon, either for the test or I forgot to look for the result. I was reading a lot of post on this and one said you only really need to shake the vial after adding reagent for 2 minutes for an accurate result.

Another helpful hint I read somewhere for adding the reagent was to flick the reagent along the black lines to help product to fall to bottom, cut along lines, then open along those lines slowly and flick again so all reagent is in the bottom. Now holding the corners of each cut end slowly move them towards each other, like you were making the package talk "Ohhh." The reagent will poor out so much easier now with the rounded area. Before I was trying to scrape it out with a small knife and it was taking too long and too messy.

This is incorrect and your results are likely incorrect or inconsistent. The instructions say how the test needs to be done to be accurate

 

[MnFish1]

Holy malarki, is this not how to do it? I am confused.

Why are you confused it’s exactly how to do it. The only thing she did not mention is to mix for 2 minutes before putting I. The vial and pressing the timer

 

[chipmunkofdoom2]

I never understood why the timeout is so short. The manual says a single battery will last for 5,000 tests. If we assume a single test has the unit on for 5 total minutes, what's the harm in doubling the timeouts? We only get 2,500 tests instead of 5,000? If you test phosphates once a day, which is highly unlikely, 5,000 tests is over 13 years of battery life. The battery will likely go bad before then. If we cut that in half by doubling the timeout, that's 6.84 years of phosphorus tests. Again, I'd be really surprised if a single battery has this kind of shelf life in it.

Had I known the timeout was this short, I wouldn't have bought this checker. There's no reason for the timeout to be so short. Not when you're bragging that a single battery will net you five thousand tests in your manual.

 

[Pmj]

My results in the "correct" method vs the "makes more sense so you don't waste a test" method:
Insert reagent - Shake 2 min - insert vial - start 3 min timer: 38
Insert reagent - start 3 min timer - shake 2 min - insert vial at 1 min left: 35

Accuracy is listed as +/- 5 PPB.. Obviously we'd need a bigger sample size, but this was around the same results when I did the test a few times before.

 

[sghera64]

My results in the "correct" method vs the "makes more sense so you don't waste a test" method:
Insert reagent - Shake 2 min - insert vial - start 3 min timer: 38
Insert reagent - start 3 min timer - shake 2 min - insert vial at 1 min left: 35

Accuracy is listed as +/- 5 PPB.. Obviously we'd need a bigger sample size, but this was around the same results when I did the test a few times before.

It’s nice that the two values are so close. But only the one with the first technique you used is reliable. As you can see from post #32 above from Bpb, it sometimes does make a difference. I don’t know why your two values are so close. I don’t know how different they “could” be by analyzing the sample 2 minutes early. It may depend on “what’s in the water”.

 

[MnFish1]

I never understood why the timeout is so short. The manual says a single battery will last for 5,000 tests. If we assume a single test has the unit on for 5 total minutes, what's the harm in doubling the timeouts? We only get 2,500 tests instead of 5,000? If you test phosphates once a day, which is highly unlikely, 5,000 tests is over 13 years of battery life. The battery will likely go bad before then. If we cut that in half by doubling the timeout, that's 6.84 years of phosphorus tests. Again, I'd be really surprised if a single battery has this kind of shelf life in it.

Had I known the timeout was this short, I wouldn't have bought this checker. There's no reason for the timeout to be so short. Not when you're bragging that a single battery will net you five thousand tests in your manual.

Hanna admits this as well.

 

[MnFish1]

My results in the "correct" method vs the "makes more sense so you don't waste a test" method:
Insert reagent - Shake 2 min - insert vial - start 3 min timer: 38
Insert reagent - start 3 min timer - shake 2 min - insert vial at 1 min left: 35

Accuracy is listed as +/- 5 PPB.. Obviously we'd need a bigger sample size, but this was around the same results when I did the test a few times before.

Yes - you'd need a bigger sample size - and a broader range of potential values'. (ie. maybe the results are comparable when the PO4 is 35 or so - but wildly different then the PO4 is 150 (or 10). There just seems (to my small brain) no reason not to do the test the way the manufacturer tells you to do it.