Hanna checker help

[Rpc07]

Hi I am trying to get some help, I ordered the newer HI774 low range p04 checker I am getting very different results. My routine is the same every time and I am waisting countless reagent packets and I am getting frustrated to say the least. Here is my routine...

Wipe down the cuvette with a microfiber towel.
Add 3-4 ml of tank water and rinse with that.
Dump tank water and wipe again.
Add the 10 ml of test water and follow the instructions from there to the end.

So far I have gotten .34, .29, .26, .19 and .03 not in that order. It’s been all over the place.

Any help is appreciated.

 

[GThompson]

Are you waiting three minutes before you get your reading?

 

[Rpc07]

Are you waiting three minutes before you get your reading?

Yes I hold down the button and wait the 3 minute countdown. I even gently shake the cuvette for 2 minutes after adding the reagent like the card says.

I’ve been using the Hanna all checker for over a year so it isn’t my first Hanna, I was just hoping for an easier p04 test.

 

[GThompson]

Yes I hold down the button and wait the 3 minute countdown. I even gently shake the cuvette for 2 minutes after adding the reagent like the card says.

I’ve been using the Hanna all checker for over a year so it isn’t my first Hanna, I was just hoping for an easier p04 test.

I’ve had some results that didn’t repeat. You list one as a .034 and the rest with two decimal places. Is there another number behind that or in front of it ?

 

[Rpc07]

I’ve had some results that didn’t repeat. You list one as a .034 and the rest with two decimal places. Is there another number behind that or in front of it ?

Mis type I meant .34

 

[JoeD_]

I have the same issues. LOVE the alk , really have no use for the phosphate checker.

 

[GThompson]

I’ve found that a lot of the results of these test that we do vary from time to time. The Hanna test with the little package of reagent is not a favorite of mine due to the fact you never really know if you got all of it out and in the cuvette. In stead of testing back to back for consistency, try waiting till the next day or even later and see if it still jumps all over

 

[ZoWhat]

With Hanna you need to calibrate them sorta like this
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R2R inside joke

 

[GThompson]

With Hanna you need to calibrate them sorta like this
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R2R inside joke

That made me bust out laughing

 

[saltyhog]

Are you making sure you have all the air bubbles out of the cuvette before starting the 3:00 minute countdown? I don't ever shake the cuvette, I hold it by the cap and invert it back and forth for 2 minutes. Never have a problem getting the reagent dissolved.

Are you using the battery that came with it? I will get some occasional goofy readings when the battery is old.

 

[DesertCitiesReefer]

Also when I use my Hanna checkers I make sure I put the curette in the same direction each time. For example the 10ml always the same direction every time.

 

[SinCityRee4r]

I use it also the key is to make sure you get all of the regent out of the packet. like with any test if you test multiple times you will have variances. I wish the reagent was a bottle with a spoon as I feel the amount to be put in may be a bit more accurate as some powder sticks into the corners and edges of the packets sometimes if you do not check.

 

[Darth.Daddy12]

Hi I am trying to get some help, I ordered the newer HI774 low range p04 checker I am getting very different results. My routine is the same every time and I am waisting countless reagent packets and I am getting frustrated to say the least. Here is my routine...

Wipe down the cuvette with a microfiber towel.
Add 3-4 ml of tank water and rinse with that.
Dump tank water and wipe again.
Add the 10 ml of test water and follow the instructions from there to the end.

So far I have gotten .34, .29, .26, .19 and .03 not in that order. It’s been all over the place.

Any help is appreciated.

Not sure why you would rinse with tank water then test tank.. you should be rinsing with rodi.. the tiny bit of residue left vs the very small test amount reagent the Hanna use could very well be the issue.

Also you appear to be running towards the upper range of the low range tester which won’t give good results. If your tank is really in the .3 range the regular phosphate checker would be a better device. The low range is best for ultra low tanks and the reasons you’re showing consistent or not are not ultra low..

Your using a scapel when you need a hammer.. the phosphorus checker is for measuring .01 levels not .3

 

[W1ngz]

Not sure why you would rinse with tank water then test tank.. you should be rinsing with rodi.. the tiny bit of residue left vs the very small test amount reagent the Hanna use could very well be the issue.

Also you appear to be running towards the upper range of the low range tester which won’t give good results. If your tank is really in the .3 range the regular phosphate checker would be a better device. The low range is best for ultra low tanks and the reasons you’re showing consistent or not are not ultra low..

Your using a scapel when you need a hammer.. the phosphorus checker is for measuring .01 levels not .3

The HI774 has a range of 0.00 to 0.90. 0.3-ish is well within range. This is not the phosphorus checker.
Specifications

Range	0.00 to 0.90 ppm

Virtually every test kit I've used always says to first rinse with the water to be tested. Rinsing with RODI dilutes the sample.
You rinse with RODI after the test is done, before storing it.

 

[saltyhog]

Not sure why you would rinse with tank water then test tank.. you should be rinsing with rodi.. the tiny bit of residue left vs the very small test amount reagent the Hanna use could very well be the issue.

Also you appear to be running towards the upper range of the low range tester which won’t give good results. If your tank is really in the .3 range the regular phosphate checker would be a better device. The low range is best for ultra low tanks and the reasons you’re showing consistent or not are not ultra low..

Your using a scapel when you need a hammer.. the phosphorus checker is for measuring .01 levels not .3

Great point about the results being at the upper range of the ULR tester. All you really need to know if it's that high is....it's that high!

About rinsing with tank water vs with RO/DI, if he is adding 10ml with a precise pipette/syringe that could be an issue. If he's filling to the 10 ml line on the cuvette it wouldn't be would it? Also I always use RO/DI to rinse my cuvette after use and there will still be some left the next time I test. Would that not dilute the test and cause falsely low results?

 

[Darth.Daddy12]

The HI774 has a range of 0.00 to 0.90. 0.3-ish is well within range. This is not the phosphorus checker.
Specifications

Range	0.00 to 0.90 ppm

Virtually every test kit I've used always says to first rinse with the water to be tested. Rinsing with RODI dilutes the sample.
You rinse with RODI after the test is done, before storing it.

I just pulled mine out and no where does it say to do this.. you are using rodi water for the test itself anyways so this can’t alter the result.. in fact my instructions on 2 Hanna’s neither ones says anything about rinsing at all..

 

[Darth.Daddy12]

Great point about the results being at the upper range of the ULR tester. All you really need to know if it's that high is....it's that high!

About rinsing with tank water vs with RO/DI, if he is adding 10ml with a precise pipette/syringe that could be an issue. If he's filling to the 10 ml line on the cuvette it wouldn't be would it? Also I always use RO/DI to rinse my cuvette after use and there will still be some left the next time I test. Would that not dilute the test and cause falsely low results?

I see what you’re saying but same could be said for using tank water and you’re using 10ml vs 1ml. So a few drops left over for the 1ml amount is going to have a much bigger change then a few drops left of the 10ml amount.

 

[Darth.Daddy12]

Will add the one thing the checker does mention for accuracy control is making sure there isn’t bubbles in the Colvet as it can throw off the readings..

 

[W1ngz]

.. you are using rodi water for the test itself anyways so this can’t alter the result..

You don't use RODI water. C1 is sample water, unreacted tank water. C2 is the same cuvette with the same sample, with the reagent added.

 

[Tuan’s Reef]

This is the Hannah you have ? .3 is within scope. I get very consistent results mine although my system is a ULN . I rinse my curvette with rodi very well and shake out any remaining water vigorously.