Hana ULR Phosphate checker

[griff500]

That's a fine reference solution if it has those properties and if it is stable.

But it was an appropriate question for MnFish to ask since we use many reference solutions that are not seawater mimics and one should not assume they are unless they say so.

Absolutely, and I don't believe I questioned his, erm, question. I have confidence in the reference solution.

The post above yours is interesting and it looks like I'm clearly not alone!

It’s coincidental that my friend and I are exploring the same problem.

I have also felt that my Hanna kit has been giving me inconsistent and higher readings than I would expect. My friend has been getting a phosphate Hanna reading of 90 and a Red Sea pro reading of 0.

This is from my tank yesterday.

A ten-fold difference.

Red Sea uses a two step process, with sulfuric acid/ammonium molybdate as a first step and tin chloride as a second step.

Hanna used a single step, potassium disulfate.

I found this article helpful “Understanding the different phosphorus tests”: https://www.hach.com/asset-get.download.jsa?id=50989301315

We have emailed Red Sea and Hanna to inquire what forms of phosphate their test will detect. Maybe all together we can get it the bottom of this!

(Credit to @RandyC who did most of this leg work...I’m just tagging along for the ride)

That's interesting and I'm glad that I'm not alone!

I wonder if the Hanna and Red Sea kits are testing different things.

I've stripped phosphate from my tank by taking actions based on the Hanna results...

 

[Randy Holmes-Farley]

Absolutely, and I don't believe I questioned his, erm, question. I have confidence in the reference solution.

I do not question your reference solution. I have no way to know about it. I do have some minor concerns about a seawater phosphate reference solution and its stability, but that is not what we are debating. In any case, if my stability concern is true, that would cause a low value, not a high one.

I'm also not defending the Hanna and am not claiming it is giving you accurate results.

I am correcting a misleading statement of yours because I did not want others to read this thread and come away with an incorrect impression of what a reference solution is:

"It’s not freshwater – it’s a reference solution."

That is not a generally true statement.

That's all I'm saying.

 

[griff500]

Were you trying to quote something? If that was meant to be something that he had said then I cannot see it in this thread and I had not seen those comments before.

I had not stated that it was a 'seawater phosphate reference solution' - just that it was a reference solution. I thought they would all be used for testing a variety of parameters and I hadn't seen any that didn't have a similar makeup. I've not looked particularly hard and it's not really that interesting or relevant to discuss alternatives.

"It’s not freshwater – it’s a reference solution." In my opinion that's not misleading - I was referring to the specific reference solution that I used and not making a generic comment about all reference solutions.

I've given the content of the reference solution that @glennf produces and that should probably be the end of the matter.

 

[Tony Thompson]

Hi Randy.

If you are asking about the reference solution when you ask 'what standard' then it was the DSR one (from the product range that @glennf has produced). If it doesn't actually contain the stated 0.08 of phosphate then it's a big coincidence that the Red Sea kit showed that level so I'm reasonably confident that it's fairly reliable, unless there are known issues with the Red Sea kit showing 0.08 results for reference kits, but then I would not expect zero for tank water.

I converted by multiplying the reading of 90 by 3 and dividing by 1,000 - not absolutely correct but at that level I couldn't see the point in being absolutely exact. Exact would be 0.28.

Thoughts?

Hi @griff500 , I must agree that the deviation between the two tests is no where near the tolerances advertised by the manufacturers. I have used both of these tests and showed very little difference except my own colour perception of the red sea wheel. However in your case the readings are so far apart that this would not appear to be the problem.

Could I just clear up somethings please,

Did you zero the Hanna meter with the tank water for the main test?

Did you zero the Hanna meter with the reference solution for the second test?

I only ask this, as pigmentation of the tank water can have an effect on the hanna reading.

Also you stated a reading on the hanna of 0.28ppm. Is this not off the scale on the Red Sea Test kit. If it is then the test should be re done using the dilution method as described in the red sea instructions. It seems odd that the colour fades to clear as you stated. IME the opposite usually happens, pale colour gradually gets stronger over time.

I personally use the Hanna Calibration Kit available for abround £16 here in the UK. This has two vials, a clear zero cal vile and coloured calibration vile. If this cal test showed the Hanna to be way out of cal I would contact Hanna.

You also stated that you had been battling phosphate for some time. In what way where you battling phosphate, was there or is there a problem with algae growth in the tank?

Hope you get to the bottom of the problem . Following your progress, good luck.

 

[Randy Holmes-Farley]

Were you trying to quote something? If that was meant to be something that he had said then I cannot see it in this thread and I had not seen those comments before.

I had not stated that it was a 'seawater phosphate reference solution' - just that it was a reference solution. I thought they would all be used for testing a variety of parameters and I hadn't seen any that didn't have a similar makeup. I've not looked particularly hard and it's not really that interesting or relevant to discuss alternatives.

"It’s not freshwater – it’s a reference solution." In my opinion that's not misleading - I was referring to the specific reference solution that I used and not making a generic comment about all reference solutions.

I've given the content of the reference solution that @glennf produces and that should probably be the end of the matter.

OK. :0

Just to respond to

"I thought they would all be used for testing a variety of parameters and I hadn't seen any that didn't have a similar makeup."

We use lots of reference solutions that are not seawater mimics, and the difference can be very important, depending on the context.

 

[griff500]

OK. :0

Just to respond to

"I thought they would all be used for testing a variety of parameters and I hadn't seen any that didn't have a similar makeup."

We use lots of reference solutions that are not seawater mimics, and the difference can be very important, depending on the context.

You might do that but I hadn't seen any of the reference solutions online that were not the type I was talking about, but it's not really important as it's been cleared up.

 

[griff500]

Hi @griff500 , I must agree that the deviation between the two tests is no where near the tolerances advertised by the manufacturers. I have used both of these tests and showed very little difference except my own colour perception of the red sea wheel. However in your case the readings are so far apart that this would not appear to be the problem.

Could I just clear up somethings please,

Did you zero the Hanna meter with the tank water for the main test?

Did you zero the Hanna meter with the reference solution for the second test?

I only ask this, as pigmentation of the tank water can have an effect on the hanna reading.

Also you stated a reading on the hanna of 0.28ppm. Is this not off the scale on the Red Sea Test kit. If it is then the test should be re done using the dilution method as described in the red sea instructions. It seems odd that the colour fades to clear as you stated. IME the opposite usually happens, pale colour gradually gets stronger over time.

I personally use the Hanna Calibration Kit available for abround £16 here in the UK. This has two vials, a clear zero cal vile and coloured calibration vile. If this cal test showed the Hanna to be way out of cal I would contact Hanna.

You also stated that you had been battling phosphate for some time. In what way where you battling phosphate, was there or is there a problem with algae growth in the tank?

Hope you get to the bottom of the problem . Following your progress, good luck.

The meter was zeroed with tank water (always in the checker, then press to start and press when it says '1'. Take out, add reagent, two minutes of inversion, put it back in and hold the button down for the 3-minute countdown.

The reference solution (0.08) showed last night a reading of 0.15 (from memory) on the Hanna and zero on the Red Sea kit.

Diluting for high range could be worth a try BUT if it is off the chart then I would expect a very dark colour to result - not a very light colour. Wouldn't that be likely?

I have had some hair algae and used GFO primarily - as it was being used I started to get growth and more polyp extension and no other changes were made, so I have to assume phosphate was being reduced and having a positive effect.

 

[Randy Holmes-Farley]

You might do that but I hadn't seen any of the reference solutions online that were not the type I was talking about, but it's not really important as it's been cleared up.

I'll let this drop, but you are trivializing important issues that can depend critically on the composition of the standard.

 

[glennf]

The reference solution was not sea water - it is a reference solution bought from a shop, detailed in a previous post. It states that it contains 0.08 phosphate - the Red Sea test showed 0.08. The Hanna test showed around 0.27. I tested multiple times with each kit and got the same readings each time.

The reference is artificial saltwater made specific for those parameters and confirmed by a double ICP test from 2 different Labs.

Anyone can make them but you need to work very clean and precise. You also need to know the purity of you basematerials.

http://www.DSRreefing.com/saltcalc

 

[Randy Holmes-Farley]

The reference is artificial saltwater made specific for those parameters and confirmed by a double ICP test from 2 different Labs.

Anyone can make them but you need to work very clean and precise. You also need to know the purity of you basematerials.

http://www.DSRreefing.com/saltcalc

Thanks, Glenn.

Have you observed them long term? What if they get warm (like in the back of a truck?)

The stability of nutrient standards has long been an issue for scientists studying seawater samples (with numerous published papers suggesting ways to gain stability, such as acidification and autoclaving).

Also, we know well that artificial seawater can precipitate calcium carbonate, which may deplete alk and also phosphate.

Hence my reason for asking about stability.

 

[Tony Thompson]

The meter was zeroed with tank water (always in the checker, then press to start and press when it says '1'. Take out, add reagent, two minutes of inversion, put it back in and hold the button down for the 3-minute countdown.

The reference solution (0.08) showed last night a reading of 0.15 (from memory) on the Hanna and zero on the Red Sea kit.

Diluting for high range could be worth a try BUT if it is off the chart then I would expect a very dark colour to result - not a very light colour. Wouldn't that be likely?

I have had some hair algae and used GFO primarily - as it was being used I started to get growth and more polyp extension and no other changes were made, so I have to assume phosphate was being reduced and having a positive effect.

Hi again, sorry I still need to clear up the question of zeroing the Hanna. Did you use the reference solution to zero the hanna before testing the same reference solution with the added reagent.

Or did you zero both times with the DT water?

With regards dilution test. I see your point with regards one would expect a much darker colour. The only reason I added this is that you mentioned the colour gradually faded and also mentioned a reading of 0. I am not a chemist so do not know the full process of the red sea test. However I have seen other tests show a false negative if the reading is off the scale. I thought I would just add the suggestion of diluted test just to eliminate that from the process.

Cheers, Tony.

 

[griff500]

I'll let this drop, but you are trivializing important issues that can depend critically on the composition of the standard.

I am not trivialising anything. I am keeping to the point rather than diving off into whatever other types of reference solutions might exist in the scientific world.

 

[griff500]

Hi again, sorry I still need to clear up the question of zeroing the Hanna. Did you use the reference solution to zero the hanna before testing the same reference solution with the added reagent.

Or did you zero both times with the DT water?

With regards dilution test. I see your point with regards one would expect a much darker colour. The only reason I added this is that you mentioned the colour gradually faded and also mentioned a reading of 0. I am not a chemist so do not know the full process of the red sea test. However I have seen other tests show a false negative if the reading is off the scale. I thought I would just add the suggestion of diluted test just to eliminate that from the process.

Cheers, Tony.

Yes, I tested the reference solution in exactly the same way as I described when testing tank water. When testing reference solution I start with that - when testing tank water I start with that. Always in the same cuvette as well... no using the two cuvettes supplied.

A dilution test couldn't hurt matters.

 

[glennf]

Thanks, Glenn.

Have you observed them long term? What if they get warm (like in the back of a truck?)

The stability of nutrient standards has long been an issue for scientists studying seawater samples (with numerous published papers suggesting ways to gain stability, such as acidification and autoclaving).

Also, we know well that artificial seawater can precipitate calcium carbonate, which may deplete alk and also phosphate.

Hence my reason for asking about stability.

Phosphate has been tested for a long period of time.
I had samples from 2015 stocked and testen it for 2 years before i decided to release the reference.

I knew this would benefit many reefers, because not everybody have knowledge or acces to pure raw material to make their own reference.

I use sterile water, products and surroundings.
So there should not be issues with activity or nutrient consumption in the reference.
Just don't leaf it into the sunlight and don't put dirty tools into the reference bottle.

Many artificial salts are oversaturated just to supply the demand for WC shedules.

As you know i put together a saltcalculator, so everybody can make their own reefsalt.
This seems to be working just fine and no problemens with percipitations within ambient temperature ranges.

Nitrate could have some Issue in long term.
It seems like it it could attrack N2 from the surroundings.
What's your thought about that?

 

[Tony Thompson]

Thanks, Glenn.

Have you observed them long term? What if they get warm (like in the back of a truck?)

The stability of nutrient standards has long been an issue for scientists studying seawater samples (with numerous published papers suggesting ways to gain stability, such as acidification and autoclaving).

Also, we know well that artificial seawater can precipitate calcium carbonate, which may deplete alk and also phosphate.

Hence my reason for asking about stability.

Hi Randy, just out of interest, with regards testing of PO4 through ICP OES,. How accurate is this form of ion testing for calculating PO4 from P, is there any deviation possible due to (PO4)2 and if so could this have any significance over the calculated result?

Please remember I am just a novice, ha ha. I just have a little bit of a discrepancy in my mind over my very limited understanding from my studies involving testing of aquarium parameters. I also seem to remember some hobbyists having conflicting results involving PO4 readings from their ICP results and there own measurements.

Would really appreciate your comments to put me on the right track again. Thanks in advance

 

[Randy Holmes-Farley]

Hi Randy, just out of interest, with regards testing of PO4 through ICP OES,. How accurate is this form of ion testing for calculating PO4 from P, is there any deviation possible due to (PO4)2 and if so could this have any significance over the calculated result?

Please remember I am just a novice, ha ha. I just have a little bit of a discrepancy in my mind over my very limited understanding from my studies involving testing of aquarium parameters. I also seem to remember some hobbyists having conflicting results involving PO4 readings from their ICP results and there own measurements.

Would really appreciate your comments to put me on the right track again. Thanks in advance

The main difference in testing aquarium water by ICP vs phosphate test is the test kits and checkers do not detect organic forms without a long, tedious procedure to break up the organics. ICP detects any form of P. SO ICP should be the same or higher than a phosphate test.

So if there are organics like DNA, RNA, phosphorylated proteins, phospholipids, all the way up to whole bacteria present in the sample sucked into the plasma, the total P value may be higher than the phosphate P value. Ehsan of Triton once said they remove bacteria by (I think) by centrifugation (translation issue may have been confounding this exact word) and so only soluble organics and not particulates are measured.

Christoph says he detects a difference here:

https://www.reef2reef.com/threads/h...sphorus-checker-accuracy.392577/#post-4736873

 

[themcfreak]

Out of curiosity (and by no means a way to discredit the test solution you are using), but why haven't you used Hanna's reference solution? I don't know that it would give a different result, but I feel you could be more certain it isn't a reference issue (or if the checker is actually misreading, then Hanna would know you used theirs and maybe it could be replaced).

 

[Randy Holmes-Farley]

Out of curiosity (and by no means a way to discredit the test solution you are using), but why haven't you used Hanna's reference solution? I don't know that it would give a different result, but I feel you could be more certain it isn't a reference issue (or if the checker is actually misreading, then Hanna would know you used theirs and maybe it could be replaced).

One thing about that standard is it only checks the machine (which may be worth doing, certainly) but not the reagents since there's no phosphate involved. It's just a color/absorption standard.

 

[Tony Thompson]

The main difference in testing aquarium water by ICP vs phosphate test is the test kits and checkers do not detect organic forms without a long, tedious procedure to break up the organics. ICP detects any form of P. SO ICP should be the same or higher than a phosphate test.

So if there are organics like DNA, RNA, phosphorylated proteins, phospholipids, all the way up to whole bacteria present in the sample sucked into the plasma, the total P value may be higher than the phosphate P value. Ehsan of Triton once said they remove bacteria by (I think) by centrifugation (translation issue may have been confounding this exact word) and so only soluble organics and not particulates are measured.

Christoph says he detects a difference here:

https://www.reef2reef.com/threads/h...sphorus-checker-accuracy.392577/#post-4736873

That`s excellent, thanks Randy, that explains a number of questions I had . Very interesting to read the link as well. As a layperson, I can now appreciate how vaporising the sample could release elements not apparent to other testing methods.

Looking back over my notes I think the discrepancy in my mind was due to some previous study I had done which may have caused me some confusion over, ion balance from ICP results and also Ca3(PO4)2. Never mind. I believe I am back on track again.

Cheers.

 

[Tony Thompson]

Out of curiosity (and by no means a way to discredit the test solution you are using), but why haven't you used Hanna's reference solution? I don't know that it would give a different result, but I feel you could be more certain it isn't a reference issue (or if the checker is actually misreading, then Hanna would know you used theirs and maybe it could be replaced).

Yes that's the one I mentioned. I use this also, just to check the photometer. I also have the ALK one. A lot cheaper in the USA though, in the UK it cost me £16.