Hanna ULR Phosphorus tester issues.

[Reefin' Alaska]

Curious, does anyone use this device?

I test every Sunday, and have steadily seen my PO4 dwindle since starting GFO on my system a month ago, but I can't quite figure out this device. I also am testing with a Red Sea Pro kit, and a Hanna PO4 checker. I've always been skepitcal of the ULR phosphorus checker, it's never really been close. 2 tests each:

Last week, the ULR last week was 37 Phos = .11 PO4. Which was slightly lower than the other 2, at .16 and .21 respectively.

I saw little reduction in PO4 overall in that 7 days so I swapped in a fresh batch of GFO.

This week:

PO4 Checker: .04 and .07
Red Sea kit: .04-.08 (Color is right between it..)
(BTW, both these values have gone down every week as you would expect with swapping in fresh GFO)

Phos ULR = 79 and 72 which is about .2 PO4 - it went up almost .1 PO4.

I have reason to believe that the ULR Phosphorus checker does not work correctly, as the other 2 have remained consistent as to what you would expect when starting GFO. The other has always been questionable to me, which is why I test with 2 other methods.

Not sure what to do here. Is there a trick to this thing I'm missing? Should I contact Hanna? New reagent? I'm lost..

 

[Darren in Tacoma]

Phos ULR = 79 and 72 which is about .2 PO4

Can you explain to me what this means?

 

[Reefin' Alaska]

Phos ULR = 79 and 72 which is about .2 PO4

Can you explain to me what this means?

The ULR Phosphorus tests Phosphorus, not PO4.

Hanna has a chart published for the conversion.

 

[living_tribunal]

Curious, does anyone use this device?

I test every Sunday, and have steadily seen my PO4 dwindle since starting GFO on my system a month ago, but I can't quite figure out this device. I also am testing with a Red Sea Pro kit, and a Hanna PO4 checker. I've always been skepitcal of the ULR phosphorus checker, it's never really been close. 2 tests each:

Last week, the ULR last week was 37 Phos = .11 PO4. Which was slightly lower than the other 2, at .16 and .21 respectively.

I saw little reduction in PO4 overall in that 7 days so I swapped in a fresh batch of GFO.

This week:

PO4 Checker: .04 and .07
Red Sea kit: .04-.08 (Color is right between it..)
(BTW, both these values have gone down every week as you would expect with swapping in fresh GFO)

Phos ULR = 79 and 72 which is about .2 PO4 - it went up almost .1 PO4.

I have reason to believe that the ULR Phosphorus checker does not work correctly, as the other 2 have remained consistent as to what you would expect when starting GFO. The other has always been questionable to me, which is why I test with 2 other methods.

Not sure what to do here. Is there a trick to this thing I'm missing? Should I contact Hanna? New reagent? I'm lost..

The Hannah phosphorous ulr is by far the most accurate consumer phosphate test kit.

The one thing that’s true with all Hanna kits is you need to make sure your testing set up procedure is consistent every time.

I get incredibly accurate readings by following these steps:

1.) I never touch the vial directly, I always use a paper towel at all times.

2.) I use a paper towel to remove the vial and then wipe it all around to ensure that it’s free of finger prints.

3.) I make sure to fill it up with the meniscus touching the line. The phosphorus test kit especially is sensitive to incorrect water amounts inside the vial. Don’t rush through this.

4.) I roll the vial once filled with tank water to ensure no micro bubbles are in it. Remove all the bubbles by tapping the top of the vial, rolling it, and a couple of slow twists.

5.) I get out a stopwatch and start it immediately after the test kit reads c2. I also prepare the reagent ahead of time to make it easy to pour into the vial.

6.) I shake for two minutes but always take an additional 20 seconds to roll the vial to get rid of all micro bubbles and also re-clean the vial eliminating finger prints.

7.) Once the test has completed, and I get my phosphorus number, I immediately clean the vial with clean rodi water and once again clean all fingerprints.

This testing procedure has always led to very consistent results with the phosphorous ulr. Best test kit I own besides Hanna alk.

 

[living_tribunal]

The ULR Phosphorus tests Phosphorus, not PO4.

Hanna has a chart published for the conversion.

It’s a simple calculation. Your number X 3.066 / 1000

 

[dwest]

I would pick a test kit and run with it. You’ll will have problems comparing one hobbyist test kit to another. I preferred Hanna ulr phosphorous over the others I have used.

 

[Reefin' Alaska]

It’s a simple calculation. Your number X 3.066 / 1000

Okay, thanks.

 

[living_tribunal]

Okay, thanks?

You’re welcome?

 

[Reefin' Alaska]

The Hannah phosphorous ulr is by far the most accurate consumer phosphate test kit.

The one thing that’s true with all Hanna kits is you need to make sure your testing set up procedure is consistent every time.

I get incredibly accurate readings by following these steps:

1.) I never touch the vial directly, I always use a paper towel at all times.

2.) I use a paper towel to remove the vial and then wipe it all around to ensure that it’s free of finger prints.

3.) I make sure to fill it up with the meniscus touching the line. The phosphorus test kit especially is sensitive to incorrect water amounts inside the vial. Don’t rush through this.

4.) I roll the vial once filled with tank water to ensure no micro bubbles are in it. Remove all the bubbles by tapping the top of the vial, rolling it, and a couple of slow twists.

5.) I get out a stopwatch and start it immediately after the test kit reads c2. I also prepare the reagent ahead of time to make it easy to pour into the vial.

6.) I shake for two minutes but always take an additional 20 seconds to roll the vial to get rid of all micro bubbles and also re-clean the vial eliminating finger prints.

7.) Once the test has completed, and I get my phosphorus number, I immediately clean the vial with clean rodi water and once again clean all fingerprints.

This testing procedure has always led to very consistent results with the phosphorous ulr. Best test kit I own besides Hanna alk.

I just tested exactly like this, just using the clock on my apex display. I fill the cuvette's with a syringe everytime and also open the reagent ahead of time, I also rinse in RO water. I cleaned with paper towel this time, as I normally don't, I just use a terry cloth.

It just read 99.

Makes no sense 7 days ago it read 39. Adding Fresh GFO. 2 fish in a 90G that I don't even feed everyday that the reading almost tripled - unless LR is leeching phosphate there is no logic to it, provided that number is correct.

It's baffling to me. About pull what little hair I have, out.

 

[Reefin' Alaska]

You’re welcome?

Sorry, wasn't a question. Lol.

 

[living_tribunal]

I just tested exactly like this, just using the clock on my apex display. I fill the cuvette's with a syringe everytime and also open the reagent ahead of time, I also rinse in RO water. I cleaned with paper towel this time, as I normally don't, I just use a terry cloth.

It just read 99.

Makes no sense 7 days ago it read 39. Adding Fresh GFO. 2 fish in a 90G that I don't even feed everyday that the reading almost tripled - unless LR is leeching phosphate there is no logic to it, provided that number is correct.

It's baffling to me.

Not sure what to tell you but just to recap, there are the main considerations, how you go about ensuring them is up to you.

1.) No fingerprints or debris on the cuvette. Just never touch it with your fingers, ever. And wipe it between use.

2.) No micro bubbles at all when performing c1 and c2.

3.) The meniscus is smack dab touching the line and you fill it precisely there every time.

4.) You shake for a full 2 minutes and once again eliminate all micro bubbles.

Eliminating the micro bubbles is the most important thing. Simply tapping on the top does not get rid of all of them. You need to make sure you can’t see any bubbles.

 

[Reefin' Alaska]

Not sure what to tell you but just to recap, there are the main considerations, how you go about ensuring them is up to you.

1.) No fingerprints or debris on the cuvette. Just never touch it with your fingers, ever. And wipe it between use.

2.) No micro bubbles at all when performing c1 and c2.

3.) The meniscus is smack dab touching the line and you fill it precisely there every time.

4.) You shake for a full 2 minutes and once again eliminate all micro bubbles.

Eliminating the micro bubbles is the most important thing. Simply tapping on the top does not get rid of all of them. You need to make sure you can’t see any bubbles.

What do you mean by meniscus? Sorry..

 

[Garets92553]

I just tested exactly like this, just using the clock on my apex display. I fill the cuvette's with a syringe everytime and also open the reagent ahead of time, I also rinse in RO water. I cleaned with paper towel this time, as I normally don't, I just use a terry cloth.

It just read 99.

Makes no sense 7 days ago it read 39. Adding Fresh GFO. 2 fish in a 90G that I don't even feed everyday that the reading almost tripled - unless LR is leeching phosphate there is no logic to it, provided that number is correct.

It's baffling to me. About pull what little hair I have, out.

How old is your rock? Phosphate will leach from rocks. I’m having that issue.

 

[living_tribunal]

What do you mean by meniscus? Sorry..

So when you fill the cuvette, the water makes a U shape right? It dips in the center of the cuvette and slopes upwards on the sides. The meniscus is the bottom of the U. You want the bottom of the U to be tangent to the line, kind of like this: U

You will definitely be getting weird results if you don't fill to precisely here each time.

 

[Reefin' Alaska]

How old is your rock? Phosphate will leach from rocks. I’m having that issue.

It was dry rock, cured for 45 days in 50G trash can. It's been about 4 months since it was cured and placed into tank.

 

[living_tribunal]

It was dry rock, cured for 45 days in 50G trash can. It's been about 4 months since it was cured and placed into tank.

If it was dry rock then it wouldn't be leaching to such an extreme degree, especially with GFO. Rock acts as a buffer, absorbing it when phosphate levels are high and leaching it when levels are low.

At 4 months in, your rock has probably binded a lot but still probably has some absorbing wiggle room.

I'd err on the testing process.

 

[Reefin' Alaska]

So when you fill the cuvette, the water makes a U shape right? It dips in the center of the cuvette and slopes upwards on the sides. The meniscus is the bottom of the U. You want the bottom of the U to be tangent to the line, kind of like this: U

You will definitely be getting weird results if you don't fill to precisely here each time.

I just fill to the 10ml line. Lol.

But I get what you're saying.

 

[living_tribunal]

I just fill to the 10ml line. Lol.

But I get what you're saying.

This is pretty important, fill it and triple check that the meniscus is what's at the line, not the slopes.

 

[Aqua Man]

Also, place the vial in the same orientation every time.
I use a mark on vial and line up with the b in ppb on the front. And everything that living tribunal said too!

 

[Reefin' Alaska]

If it was dry rock then it wouldn't be leaching to such an extreme degree, especially with GFO. Rock acts as a buffer, absorbing it when phosphate levels are high and leaching it when levels are low.

At 4 months in, your rock has probably binded a lot but still probably has some absorbing wiggle room.

I'd err on the testing process.

Interesting.

When the bottom of the U shape is at the line, it read 43..

Curious.