How do you ensure accurate WC testing?

[Fishjayfonz]

Hey all,

Curious to see how others test their systems to ensure accurate results for example by running multiple series, standards, brands etc.

Currently I use the AF kits for Ca & Mag, and Hanna Checkers for Alk & PO4. Recently I've been trying to fine tune my testing methods to ensure the numbers I'm getting are reliable. I'll check readings by running Ca & Mag using Salifert kits as well as running samples against a standard provided in the AF kits for Ca & Mag. I'll also send off a monthly ICP when I can.

Lately I have become distrusting of the ULR Hanna checker for PO4 as it's readings conflict with ICP (~0.30 checker vs. 0.02 ICP), so finding a way to reliably test for PO4 is my priority right now, without having to rely on external ICP testing.

Would love to hear your guys methods and how you drive for precision!

Fair Winds & Happy Reefing,

Jason

 

[peterhos]

Hey all,

Curious to see how others test their systems to ensure accurate results for example by running multiple series, standards, brands etc.

Currently I use the AF kits for Ca & Mag, and Hanna Checkers for Alk & PO4. Recently I've been trying to fine tune my testing methods to ensure the numbers I'm getting are reliable. I'll check readings by running Ca & Mag using Salifert kits as well as running samples against a standard provided in the AF kits for Ca & Mag. I'll also send off a monthly ICP when I can.

Lately I have become distrusting of the ULR Hanna checker for PO4 as it's readings conflict with ICP (~0.30 checker vs. 0.02 ICP), so finding a way to reliably test for PO4 is my priority right now, without having to rely on external ICP testing.

Would love to hear your guys methods and how you drive for precision!

Fair Winds & Happy Reefing,

Jason

 

[peterhos]

Hi There Worried to hear your comments on the Hanna checker(s) which I enjoy using. I have been thinking of sending off a Triton or similar test, but do we in fact really know for sure which test regime to trust? Apologies for not answering the question…

 

[KStatefan]

Follow instructions and do it the same way each time is really the only thing you can do.

Edited to add last ICP results

Water sample taken at the same time

Me using Hanna HI736 0.49 mg/L
Oceamo 0.436 mg/L
Reeflabs calculated 0.548 mg/L

 

[Sisterlimonpot]

Would love to hear your guys methods and how you drive for precision!

I think it's widely accepted in the hobby that chasing precision is a fool's errand.

we've come to accept that these hobby grade tests are consistent but far from precise. Which is the reason why you read so many statements about tracking trends are more important than knowing precise numbers.

As long as your procedures for testing are the same everytime you'll get consistent results.

 

[Troylee]

Hey all,

Curious to see how others test their systems to ensure accurate results for example by running multiple series, standards, brands etc.

Currently I use the AF kits for Ca & Mag, and Hanna Checkers for Alk & PO4. Recently I've been trying to fine tune my testing methods to ensure the numbers I'm getting are reliable. I'll check readings by running Ca & Mag using Salifert kits as well as running samples against a standard provided in the AF kits for Ca & Mag. I'll also send off a monthly ICP when I can.

Lately I have become distrusting of the ULR Hanna checker for PO4 as it's readings conflict with ICP (~0.30 checker vs. 0.02 ICP), so finding a way to reliably test for PO4 is my priority right now, without having to rely on external ICP testing.

Would love to hear your guys methods and how you drive for precision!

Fair Winds & Happy Reefing,

Jason

It’s really not that serious! Hannah is fine for what they are… don’t chase the numbers! In fact I don’t even bother testing unless there’s a problem! It’s the best approach I’ve found personally.

 

[JimWelsh]

I think it's widely accepted in the hobby that chasing precision is a fool's errand.

we've come to accept that these hobby grade tests are consistent but far from precise. Which is the reason why you read so many statements about tracking trends are more important than knowing precise numbers.

As long as your procedures for testing are the same everytime you'll get consistent results.

You are confusing precision and accuracy. Consistency is synonymous with precision.

 

[Dan_P]

Hey all,

Curious to see how others test their systems to ensure accurate results for example by running multiple series, standards, brands etc.

Currently I use the AF kits for Ca & Mag, and Hanna Checkers for Alk & PO4. Recently I've been trying to fine tune my testing methods to ensure the numbers I'm getting are reliable. I'll check readings by running Ca & Mag using Salifert kits as well as running samples against a standard provided in the AF kits for Ca & Mag. I'll also send off a monthly ICP when I can.

Lately I have become distrusting of the ULR Hanna checker for PO4 as it's readings conflict with ICP (~0.30 checker vs. 0.02 ICP), so finding a way to reliably test for PO4 is my priority right now, without having to rely on external ICP testing.

Would love to hear your guys methods and how you drive for precision!

Fair Winds & Happy Reefing,

Jason

Have you run PO4 standards in PO4 Checker and ICP? Unless you do that, it is impossible to say which test is more accurate.

 

[JimWelsh]

Have you run PO4 standards in PO4 Checker and ICP? Unless you do that, it is impossible to say which test is more accurate.

What PO4 standards in an ASW matrix do you recommend?

 

[GARRIGA]

Not popular but API and a magnetic stirrer accurate enough to maintain a proper WC management. I’d be more concern using the same tools to test tank and new water based on both having similar within range parameters fir those where a large change is devastating than hoping that complex tester is off because of my human error.

Salinity, temperature, pH and kh what I focus on. Know of no evidence that large swings in calcium, magnesium or trace will shock life. Those that matter can all be corrected within range to that it replaces.

 

[Muffin87]

Hey all,

Curious to see how others test their systems to ensure accurate results for example by running multiple series, standards, brands etc.

Currently I use the AF kits for Ca & Mag, and Hanna Checkers for Alk & PO4. Recently I've been trying to fine tune my testing methods to ensure the numbers I'm getting are reliable. I'll check readings by running Ca & Mag using Salifert kits as well as running samples against a standard provided in the AF kits for Ca & Mag. I'll also send off a monthly ICP when I can.

Lately I have become distrusting of the ULR Hanna checker for PO4 as it's readings conflict with ICP (~0.30 checker vs. 0.02 ICP), so finding a way to reliably test for PO4 is my priority right now, without having to rely on external ICP testing.

Would love to hear your guys methods and how you drive for precision!

Fair Winds & Happy Reefing,

Jason

Change the batteries of your Hanna PO4 with brand new ones.
If you use lanthanum chloride, the Hanna will read higher. Happened a bunch of times to me.

 

[Dan_P]

What PO4 standards in an ASW matrix do you recommend?

I have used the Ricca 1000 ppm PO4 standard in the past.

Phosphate Standard 120 mL 1000 ppm, Ricca 5839-4

Phosphate Standard 1000 ppm 120 mL Poly Natural Shelf Life: 18 months Hazmat: No MSDS CofA

www.sycamorelifesciences.com

 

[JimWelsh]

I have used the Ricca 1000 ppm PO4 standard in the past.

Phosphate Standard 120 mL 1000 ppm, Ricca 5839-4

Phosphate Standard 1000 ppm 120 mL Poly Natural Shelf Life: 18 months Hazmat: No MSDS CofA

www.sycamorelifesciences.com

Not in an ASW matrix, though, and would need dilution in order to work with Hanna ULR phosphate/phosphorus checkers. EDIT: A dilution beyond the capabilities of most hobbyists to do with any real accuracy.

 

[Dan_P]

Not in an ASW matrix, though, and would need dilution in order to work with Hanna ULR phosphate/phosphorus checkers.

Nothing like a little investment in glassware couldn’t fix :)

@Rick Mathew do you have better choice, something that doesn’t require glassware or belonging to an institution? What about a multi parameter option?

 

[JimWelsh]

Nothing like a little investment in glassware couldn’t fix :)

I think every hobbyist should have, at a bare minimum, a 1000 mL Class A volumetric flask.

 

[BaliReefBox]

I use the hanna ulr phophate checker and get readings as follows with the same sample.
1st 0.09
2nd 0.02
3rd 0.06
4th 0.06

I started running multi tests when I had a reading of 0.01 down from the previous days check of 0.09... to me it is all over the shot. I do the exact same procedure everytime so I would expect more consistency. I am not chasing a specific number hard and fast, but more the trend

 

[Dan_P]

I use the hanna ulr phophate checker and get readings as follows with the same sample.
1st 0.09
2nd 0.02
3rd 0.06
4th 0.06

I started running multi tests when I had a reading of 0.01 down from the previous days check of 0.09... to me it is all over the shot. I do the exact same procedure everytime so I would expect more consistency. I am not chasing a specific number hard and fast, but more the trend

With an accuracy of +/- 0.02 ppm, the only odd reading seems to be 0.02 ppm. Just imagine what your “readings” would be using a kit with a color chart :)

Are your vials scratch free? Do you always place the vial in the Checker oriented in exactly the same way? I am trying to come up with ideas that might up your game.

 

[BaliReefBox]

With an accuracy of +/- 0.02 ppm, the only odd reading seems to be 0.02 ppm. Just imagine what your “readings” would be using a kit with a color chart :)

Are your vials scratch free? Do you always place the vial in the Checker oriented in exactly the same way? I am trying to come up with ideas that might up your game.

mate vials free of scratches, 10ml to the front each time, wiped with micro fibre cloth each time... I am not really concerned as I treat these readings as indicative only and use to see trends. I just run the tests a few times and average the score.
I also agree that they are keeps better than trying to guess colors especially with my dodgy eyes:dizzy-face:

 

[Dan_P]

mate vials free of scratches, 10ml to the front each time, wiped with micro fibre cloth each time... I am not really concerned as I treat these readings as indicative only and use to see trends. I just run the tests a few times and average the score.
I also agree that they are keeps better than trying to guess colors especially with my dodgy eyes:dizzy-face:

OK, sounds like everything under control then.

 

[Fishjayfonz]

I think it's widely accepted in the hobby that chasing precision is a fool's errand.

we've come to accept that these hobby grade tests are consistent but far from precise. Which is the reason why you read so many statements about tracking trends are more important than knowing precise numbers.

As long as your procedures for testing are the same everytime you'll get consistent results.

I agree, we can only get so accurate with hobby grade kits but trends are better indicators anyways.

I have consistently gotten very different readings specifically for PO4 between the hanna checker and ICP so figuring out which trend to rely on has been my issue