Making your own Testing Reference media (?)

[ZoWhat]

I've heard again today in a discussion with a Top-tier vendor that, "that your testing methods are only as good as how close the test is to 'exactly-known' references"

meaning that what ever your testing method is for, say, NO3 ... is only as good as you running a test with exactly deadon 1ppm NO3 solution and your test result using that substance is as close to that test# as possible.

QUESTION:

I have a digital scale capable of measuring out finite grams... potential grams of 'what' for each test is an unknown to me. Help

How do I make my own reference substances for?:

* Hanna ULR Phosphorus (i.e. PO4 when # is converted)
* Hanna Nitrtates
* Hanna Alkalinity

* Salifert Calcium
* Salifert Magnesium
* Sailfert Iodine

There has to be a way to cross reference and check so I can say, "my Hanna Nitrate test is off -0.2 points compared to this exact known substance because my 1ppm nitrate shows 0.8 on my Hanna Checkr"


.

 

[ZoWhat]

Anyone?
@Randy Holmes-Farley

 

[ZoWhat]

NM

.... seeing Hanna has some of their own reference solutions sale

 

[mdb_talon]

NM

.... seeing Hanna has some of their own reference solutions sale

Many of the ones they sell are useless in my opinion. Vials with colors. It just confirms the device works...not that regeants work, procedures are correct, etc. Better to use saltwater solutions with known values and do the full test. Maybe hanna makes those also though so maybe that is what you seeing

 

[mdb_talon]

Someone on here recently posted this. Never used it yet I was going to try it, but out of stock.

Multi-Reference Calibration Solution (100 ml) - Fauna Marin

Free Shipping on Everything, Rewards, Free Swag, Price Matching & Free Returns.

www.saltwateraquarium.com

 

[X-37B]

All hobby test kits are really as accurate as they need to be, imo.
Having backup tests to verify a wierd reading is all I use.
Verifing with an icp test is always an option.
The above solution is interesting as I have never seen it before.
Has anyone used it?

 

[mdb_talon]

All hobby test kits are really as accurate as they need to be, imo.

I have always pretty much thought the same thing until my issue with hanna alk checker. Luckily i always test old/new regeant when i do switch to new package otherwise would have been wrong by over 2 dkh which i think is pretty significant. Thats my main drive to use a standard. When in stock i am curious to how that product i linked works. Going to compare to all my tests the same day i send ICP sample to compare the 3.

Other than that alk checker regeant though ya in many years of testing i never really had issues. Seem quite consistent between regeant batches and matched fairly close to ICP so i feel it close enough for what i am doing.

 

[X-37B]

I have always pretty much thought the same thing until my issue with hanna alk checker. Luckily i always test old/new regeant when i do switch to new package otherwise would have been wrong by over 2 dkh which i think is pretty significant. Thats my main drive to use a standard. When in stock i am curious to how that product i linked works. Going to compare to all my tests the same day i send ICP sample to compare the 3.

Other than that alk checker regeant though ya in many years of testing i never really had issues. Seem quite consistent between regeant batches and matched fairly close to ICP so i feel it close enough for what i am doing.

Same here. I am going to get it when it is in stock.
The alk standard is easy to make.

I did mention in another post that my hanna alk was reading .5-.7 higher consistently.
The alk standard did prove it was off.
Funny thing is I changed the battery and it was within .1 again.

I have been lucky as I never had a bad alk reagent.

 

[Dan_P]

Someone on here recently posted this. Never used it yet I was going to try it, but out of stock.

Multi-Reference Calibration Solution (100 ml) - Fauna Marin

Free Shipping on Everything, Rewards, Free Swag, Price Matching & Free Returns.

www.saltwateraquarium.com

Yep, multi-parameter solutions are the way to go.

 

[X-37B]

BRS has it in stock as I just purchased one.

 

[ZoWhat]

Yep, multi-parameter solutions are the way to go.

Now that's what I'm talking about... a lab grade solution that has exacting test #s

I don't trust Hanna reference vials bc over time they would STAIN the glass and the glass would get scratched, throwing OFF test #s

With this FM reference solution, I'll now know if my Hanna reagents are off or the glass vials need to be replaced due to staining/scratches

 

[mdb_talon]

BRS has it in stock as I just purchased one.

Curious to see how it goes and how close it is to your tests let us know. Once saltwateraquarium gets it in stock i believe I will get it as well.

 

[Dan_P]

Now that's what I'm talking about... a lab grade solution that has exacting test #s

I don't trust Hanna reference vials bc over time they would STAIN the glass and the glass would get scratch throwing OFF test #s

The Hanna references only test that the photometer is working properly. Your question is broader: “is the test system working, that is, are the chemical and photometer together giving me the right number?”

 

[ZoWhat]

The Hanna references only test that the photometer is working properly. Your question is broader: “is the test system working, that is, are the chemical and photometer together giving me the right number?”

Can you word this a different way? I'm really not following what you are saying.... Are you saying the reference vials only gives a PASS or FAIL photometer check?

With FM multi-para, I should be able to test with a checker an exact ICP tested #.

If my Checker says it's 9.4ppm of 'whatever' and its suppose to be exactly 10ppm.... then I know by how much the Checker is truly OFF. could be the reagent. Could be the vial. Could be the colorimeter eye. But I'll know by how much it's OFF :

 

[mdb_talon]

If my Checker says it's 9.4ppm of 'whatever' and its suppose to be exactly 10ppm.... then I know by how much the Checker is truly OFF. could be the reagent. Could be the vial. Could be the colorimeter eye. But I'll know by how much it's OFF :

If you are using the \FM solution then yes this would be correct (it assumes the error variance is linear across different ranges of alkalinity and assumes that FM solution is perfect). A solution like this can be used to confirm the reagent is good, the test process is good, and that the checker itself is mechanically functioning correctly.

If you are talking about using the hanna standard solution vials though it does not give you the same information. You just get two vials (the zero vial and the reference vial tinted to deliver a specific reading) It only tells you that the checker is functioning properly and it is not possible to use that to test your reagent batch.

 

[Dan_P]

Can you word this a different way? I'm really not following what you are saying.... Are you saying the reference vials only gives a PASS or FAIL photometer check?

With FM multi-para, I should be able to test with a checker an exact ICP tested #.

If my Checker says it's 9.4ppm of 'whatever' and its suppose to be exactly 10ppm.... then I know by how much the Checker is truly OFF. could be the reagent. Could be the vial. Could be the colorimeter eye. But I'll know by how much it's OFF :

There are two steps in the Hanna test that can be ”off”. First in line is the chemical reaction that makes the color. How you sample the aquarium water, fill the vial, follow the steps, add the chemicals, and clean the vial before placing it in the Checker affect the results. Even the quality of the chemicals used in the test can be “off”. The other major component that can be “off” is the Checker itself.

The Hanna reference standard only tells you if the Checker is performing correctly. The multi-parameter reference standard tells you if entire analytical process is performing correctly. If you need to determine whether there is an issue with the color generation process in the first half of the process or the color measuring done by the Checker, the Hanna reference standard would be useful. Often, the multi-parameter reference standard is tested at several dilutions to determine whether the test is working at all concentrations.

Make sense now?

 

[gbroadbridge]

Same here. I am going to get it when it is in stock.
The alk standard is easy to make.

I did mention in another post that my hanna alk was reading .5-.7 higher consistently.
The alk standard did prove it was off.
Funny thing is I changed the battery and it was within .1 again.

I have been lucky as I never had a bad alk reagent.

Yes, I've found that (in my experience) there can be +-0.4 dkh between different batches of Hanna reagents, which I believe is within the stated spec of the instrument.

In terms of absolute accuracy, I've also found that the 10ml lines printed on the cuvettes, can be significantly out, I have one where the line actually shows 9.1ml rather than ten when correctly filled meaning at the meniscus of the water. You can check that using a 5ml syringe from a drugstore, or even better with a lab grade micro pipette.

I use Randys titration with HCl on a known size sample and ph probe to check out the real Alk and mark the difference on the Hanna Reagent bottle when I open a new one.

Good luck!

 

[X-37B]

Ok got mine in and ran some test this morning.
Still have to run po4 and no3.
Fauna specs:

My tank this morning.
SG 1.0265
Temp 79
Alk Hanna 155-8.68
Alk salifert .46-8.3
Ca salifert .16-420
Mag salifert .11 1335

Fauna Reference Solution:
Alk reference 6.6
Alk Hanna 122-6.83
Alk salifert .57-6.55
CA reference 444
CA salifert .16-420
Mag reference 1346
Salifert .12 1320

My take: Hanna alk is still 0.3-0.4 higher.
My desired alk is 8+- 0.3 as I have raised it over the last month from 7. I just replaced my co2 tank yesterday and the numbers look good.
Salifert alk was almost an exact match.
CA and Mag are close enough for my system as compaired to salifert.

I will test po4 and no3 later today and report back.

It will be interesting to see other results.

 

[gbroadbridge]

Ok got mine in and ran some test this morning.
Still have to run po4 and no3.
Fauna specs:

My tank this morning.
SG 1.0265
Temp 79
Alk Hanna 155-8.68
Alk salifert .46-8.3
Ca salifert .16-420
Mag salifert .11 1335

Fauna Reference Solution:
Alk reference 6.6
Alk Hanna 122-6.83
Alk salifert .57-6.55
CA reference 444
CA salifert .16-420
Mag reference 1346
Salifert .12 1320

My take: Hanna alk is still 0.3-0.4 higher.
My desired alk is 8+- 0.3 as I have raised it over the last month from 7. I just replaced my co2 tank yesterday and the numbers look good.
Salifert alk was almost an exact match.
CA and Mag are close enough for my system as compaired to salifert.

I will test po4 and no3 later today and report back.

It will be interesting to see other results.

Well, the Hanna Alk is within the spec of the instrument, and is pretty close to the difference I see when I compare with a direct HCl titration to determine Alk.

The variation of the Hanna Alk reagent between batches can be up to +- 0.3dkh in my experience.