Chemetrics or Mardel, which should I trust?

[Crashjack]

I’m quarantining a H. Melanurus wrasse and have been ramping-up copper. I tested with my Chemetrics test today, and though the test isn’t easy to read (way easier than API), best I could tell looking at under different lighting and different angles, my copper was at 2.0 mg/l as it matched that sample exactly as far as my eye could tell. Also, when I placed the sample in the low range tester, it was obviously considerably higher than 1.0 mg/l, which is as high as the low range goes. The problem is, I’ve only added 10.5 ml of copper to 10 gallons of water (10 actual gallons). According to the Mardel Coppersafe bottle, full-dosage would be 12.5 ml for 10 gallons. I’ve been using a 5 ml syringe and adding small amounts twice per day. I’ve dosed 9 times with most doses being 1 ml (the first few doses were a little larger). I guess there could be a margin of error to make up the 2 ml I’m short, but I would have to be off by around .2 ml each dose. I also guess it is possible my Sterilite container is leaching copper from a previous quarantine, but that seems like a lot of leaching. As the title of my thread states, which should I trust?

 

[Maritimer]

I would trust the test kit over the instructions on the bottle.

~Bruce

 

[Crashjack]

I would trust the test kit over the instructions on the bottle.

~Bruce

Logical, but I'm nervous because this is more than just a prophylactic treatment. I got two fairy wrasses with the Melanurus, and both died before I started treatment. They were eating initially but were reclusive. The first dropped dead within 12 hours of it eating. The second became lethargic and slowed eating before medication, and then stopped eating and died right after I started medicating. I suspect flukes but am not sure. If it was something like velvet, I want to make double-dog sure I'm running proper copper levels before introducing the Melanurus to the DT.

 

[Maritimer]

Understood.

Assuming you're using a chelated copper? Copper will do nothing for flukes, but a freshwater dip will both provide some relief for velvet _and_ confirm the presence of flukes. (Fish should ideally be in decent condition before starting the dip - though some folks tend to feel that if a fish doesn't make it through a properly executed freshwater dip, they weren't going to make it anyway . . . )

Great article and video on freshwater dip here: https://www.reef2reef.com/threads/video-how-to-do-a-freshwater-dip.286639/#post-3487082

I'd still trust the test kit - especially the Chemetrics kit - over the back of the bottle. It really should be telling you how much copper is actually in the water.

~Bruce

 

[Crashjack]

Understood.

Assuming you're using a chelated copper? Copper will do nothing for flukes, but a freshwater dip will both provide some relief for velvet _and_ confirm the presence of flukes. (Fish should ideally be in decent condition before starting the dip - though some folks tend to feel that if a fish doesn't make it through a properly executed freshwater dip, they weren't going to make it anyway . . . )

Great article and video on freshwater dip here: https://www.reef2reef.com/threads/video-how-to-do-a-freshwater-dip.286639/#post-3487082

I'd still trust the test kit - especially the Chemetrics kit - over the back of the bottle. It really should be telling you how much copper is actually in the water.

~Bruce

I'm using cheated copper (Coppersafe). Since the fish were in the QT and I planned to medicate anyway, I performed round one of GC when I started ramping-up copper.

 

[Maritimer]

Any initial flukes _should_ be wiped out then. (I have heard tales of Prazi-resistant flukes...) One more round, appropriately timed, should take out any second-generation flukelets.

~Bruce

 

[coweyes298]

I have interesting testing result using Chematric this time as well. This is the second time I use copper to treat fish. This time I have dosed less than 1 gallon water per 2 ml coppersafe dosage to achieve 2 ppm concentration. I am sure I filled my 2.5 gallon bucket to the 2 gallon line ( it is a 2.5 gallon semi transparent measuring bucket from LOWE'S with indication on outside). After I dosed 4 ml of coppersafe into that 2 gallon of newly mixed saltwater, ( I did stir it a little bit after adding copper), I measured with chematric kit and it is between 2 and 3 ppm but more close to 3 ppm for me. I tried API test kit as well but I am very bad at telling the color from API so there is no result...

I don't remember what was the dosage to get 2 ppm I had the first time I used copper and chematirc ( it was this July). If I am correct I calculated the QT water volume to approximation and dosed 1 gallon/2ml coopersafe at that time, so it might not be a precise dosage. I need to find the memo I kept. Glad that I documented every step and measuring result while I treat fish.

 

[Gmj4409]

I have interesting testing result using Chematric this time as well. This is the second time I use copper to treat fish. This time I have dosed less than 1 gallon water per 2 ml coppersafe dosage to achieve 2 ppm concentration. I am sure I filled my 2.5 gallon bucket to the 2 gallon line ( it is a 2.5 gallon semi transparent measuring bucket from LOWE'S with indication on outside). After I dosed 4 ml of coppersafe into that 2 gallon of newly mixed saltwater, ( I did stir it a little bit after adding copper), I measured with chematric kit and it is between 2 and 3 ppm but more close to 3 ppm for me. I tried API test kit as well but I am very bad at telling the color from API so there is no result...

I don't remember what was the dosage to get 2 ppm I had the first time I used copper and chematirc ( it was this July). If I am correct I calculated the QT water volume to approximation and dosed 1 gallon/2ml coopersafe at that time, so it might not be a precise dosage. I need to find the memo I kept. Glad that I documented every step and measuring result while I treat fish.

Brew12 had a thread on proper dosing for Coppersafe recently where he questioned the label dosing instructions. Good read.

 

[Crashjack]

Brew12 had a thread on proper dosing for Coppersafe recently where he questioned the label dosing instructions. Good read.

I saw that after I posted. The problem is, I’m getting similar results to the guy who posted the videos. At dosing 1.05 ml per gallon, I’m getting right at 2 mg/l on Chemetrics. I know I have some potential margin of error with my gallons and milliliters. He measured 1.25 ml per gallon and did so fairly precisely and got between 2 and 3 on Chemetrics.

 

[Gmj4409]

I saw that after I posted. The problem is, I’m getting similar results to the guy who posted the videos. At dosing 1.05 ml per gallon, I’m getting right at 2 mg/l on Chemetrics. I know I have some potential margin of error with my gallons and milliliters. He measured 1.25 ml per gallon and did so fairly precisely and got between 2 and 3 on Chemetrics.

Yes - it’s pretty confusing between dosing & then trying to read a test kit. I’ve chosen to go slow & just rely on the Chemetrics test.

 

[coweyes298]

Same here. I don't think the 2ml/gallon dosage from other thread is valid to me when I use Chematric kit. It is some how lesser than the 2ml/gallon.

 

[Gmj4409]

Same here. I don't think the 2ml/gallon dosage from other thread is valid to me when I use Chematric kit. It is some how lesser than the 2ml/gallon.

Agreed

 

[Crashjack]

I emailed Chemetrics and will share their response.

 

[Brew12]

I posted this on the other thread but figured I would post it here, too. Copper dosing just shouldn't be this difficult.

https://www.chemetrics.com/index.ph...e=copper.pdf.37bd5e3fa1095d699a8b9e8eaba68bab

"Interference Information: This chemistry measures fully ionized solubilized copper. It does not measure suspended, insoluble particulate copper, copper attached to large organic molecules, or chelated copper."

Notice that they don't recommend this test kit for chelated copper. I wonder if that is the cause of all the varied results using this test kit.

 

[Crashjack]

My question and Chemetrics response:

Me: I purchased your kit Copper (soluble) — CHEMets® Visual Kit Catalog No.: K-3510 to measure copper levels when treating saltwater fish. The copper product I'm using is Coppersafe (chelated copper). The test results I'm getting are higher than what it should be based on the dosage listed on the bottle, and I'm trying to determine which is accurate. I've dosed approximately 1.05 ml of the product per gallon, which should yield a little over 1 mg/l of copper. I'm getting 2.0, spot-on with your test kit. Any help or advice would be greatly appreciated.

Technical Services Rep: Are you waiting only one minute for the color to develop instead of 2 minutes (see Test Method section of instructions)?

Please note that the accuracy of this kit is +/- one color standard increment. Therefore, a 1 ppm standard can read from 0.8 – 2 ppm.

Best regards,

I asked a follow-up question and will share when I get a response.

 

[Brew12]

My question and Chemetrics response:

Me: I purchased your kit Copper (soluble) — CHEMets® Visual Kit Catalog No.: K-3510 to measure copper levels when treating saltwater fish. The copper product I'm using is Coppersafe (chelated copper). The test results I'm getting are higher than what it should be based on the dosage listed on the bottle, and I'm trying to determine which is accurate. I've dosed approximately 1.05 ml of the product per gallon, which should yield a little over 1 mg/l of copper. I'm getting 2.0, spot-on with your test kit. Any help or advice would be greatly appreciated.

Technical Services Rep: Are you waiting only one minute for the color to develop instead of 2 minutes (see Test Method section of instructions)?

Please note that the accuracy of this kit is +/- one color standard increment. Therefore, a 1 ppm standard can read from 0.8 – 2 ppm.

Best regards,

I asked a follow-up question and will share when I get a response.

Wow.. and isn't the next standard up from 2 a 3? So a 2ppm standard could read between 1ppm and 3ppm?

 

[Gmj4409]

Wow.. and isn't the next standard up from 2 a 3? So a 2ppm standard could read between 1ppm and 3ppm?

Thanks for the help folks. I am amazed this is such a struggle for all of us. The last few years of Velvet & ick have brought the challenge of dosing copper for all new fish to the forefront but testing/dosing doesn’t seem to have kept up. I started with API, went to Chemetrics & now feel like I need to keep looking.
Has anyone looked into the Hanna copper offering? They are in their catalogue but don’t seem to call out yea/nay for saltwater. I haven’t seen them in hobby so they may not be compatible.

 

[Gmj4409]

Thanks for the help folks. I am amazed this is such a struggle for all of us. The last few years of Velvet & ick have brought the challenge of dosing copper for all new fish to the forefront but testing/dosing doesn’t seem to have kept up. I started with API, went to Chemetrics & now feel like I need to keep looking.
Has anyone looked into the Hanna copper offering? They are in their catalogue but don’t seem to call out yea/nay for saltwater. I haven’t seen them in hobby so they may not be compatible.

I contacted Hanna support regarding their Copper Checker. Regretfully, response was “the scientific method used for copper is not compatible with salt water”.

 

[Crashjack]

I wanted to update my correspondence with Chemetrics and will update in the other thread as well. My questions and Chemetrics responses:

Me: I purchased your kit Copper (soluble) — CHEMets® Visual Kit Catalog No.: K-3510 to measure copper levels when treating saltwater fish. The copper product I'm using is Coppersafe (chelated copper). The test results I'm getting are higher than what it should be based on the dosage listed on the bottle, and I'm trying to determine which is accurate. I've dosed approximately 1.05 ml of the product per gallon, which should yield a little over 1 mg/l of copper. I'm getting 2.0, spot-on with your test kit. Any help or advice would be greatly appreciated.

"Sarah" Technical Services Rep: Are you waiting only one minute for the color to develop instead of 2 minutes (see Test Method section of instructions)?

Please note that the accuracy of this kit is +/- one color standard increment. Therefore, a 1 ppm standard can read from 0.8 – 2 ppm.

Me: I didn’t see the “wait 1 minute” part until after I tested. So if I follow what you are saying about the color standard, there is really no way to pinpoint 1.5 - 2.0 ppm, which is what I’m shooting for as the margin of error is likely to be over 1 ppm. Is that correct? Just curious, what is the reason for the low range precision (.2 ppm increments), if the margin of error spans the entire scale?

"Melanie" Technical Services Rep: To clarify, your test result of 2 ppm is within the accuracy expectation of the test kit for a sample that contains approximately 1 ppm copper.

As Sarah mentioned, the accuracy of this visual kit is +/- color standard increment; in other words, the accuracy is dependent upon the available increments. Specifically, the color standard increments for this kit are:
0, 0.1, 0.2, 0.3, 0.4, 0.6, 0.8, 1.0 and 1, 2, 3, 4, 5, 6, 7, 8, 10 ppm. So, the accuracies of this test kit are: +/-0.1 ppm between 0 & 0.4 ppm, +/-0.2 between 0.4 & 1 ppm, +/-1 ppm between 1 & 8 ppm, +/-2 ppm between 8 & 10 ppm. Increments of 0.2 ppm are possible to distinguish visually in the 0-1 ppm range with the C-3501 (round) comparator, but for concentrations greater than 1 ppm (i.e. with the C-3510 flat comparator), increments of 0.2 ppm are essentially indistinguishable.

Also to clarify, the intensity of the developed color in the test ampoule doesn’t change significantly between 1 and 2 minutes of color development. Seawater samples will cause the reagent to precipitate, which can make it more difficult to make a visual color match. Since the precipitation worsens with time, the shorter color development time of 1 minute is recommended for seawater samples simply to minimize the impact of the precipitation while making a visual color match.

Me: Thanks for the thorough explanation! So if I got a reading of say 2.5 ppm (color between 2 ppm and 3 ppm samples), would it be safe to say the copper level was at a minimum of 1.5 ppm and no greater than 3.5 ppm, assuming I took the reading after 1 minute?

"Melanie" Technical Services Rep: Correct.

Me: Also, does the fact that the product I’m using is chelated copper change anything?

"Melanie" Technical Services Rep: That’s a good question. We know that the test kit chemistry doesn’t measure some chelated copper (e.g. copper chelated with EDTA). However, Mardel Laboratories, the manufacturer of Coppersafe, reported many years ago that K-3510 accurately measures the copper in their product. We don’t know what the chelant is because that’s proprietary. It has dawned on me today that Mardel would have taken measurements at 2 minutes of color development, not at 1 minute (the 1 minute color development time for seawater samples is a relatively new procedure). It’s possible that since it’s chelated, the copper in Coppersafe may take more than 1 minute to develop full color, so it would be a good idea for you to confirm that results obtained at 1 and 2 minutes do agree with your seawater samples.

I don't know if this is earth-shattering information, but I find some things interesting: 1) Mardel confirmed in the past that the Chemectrics test kit accurately measured Coppersafe. 2) The margin of error is huge but at least Chemectrics identifies it. I could find no information in regards to margin of error with API or Hach test kits, though they obviously have some margin of error. 3) If the chelant used in Coppersafe doesn't effect the Chemectrics test, I have to wonder if any of these kits are better than the others as far as accuracy is concerned (API could be accurate but since I can't read it, it doesn't matter). 4) Without a known sample concentration, there is really no way to say which test is accurate and which isn't. I don't see a way to get a known sample concentration.

 

[Gmj4409]

Wow that is a lot to digest. Great work bringing it all together. I’m with you - can’t read the API. Wonder if BRS would consider taking this on??