Hanna LR Cu unreliable

[pseudorand]

I can't seem to get a consistent reading from my Hanna LR Cu test. Does anyone else have this problem?

This morning I asked about QT problems and someone suggested copper. So I pulled out my handy Hanna low-range Copper checker and got results from 0 to 178 in a series of 6 tests.

Just now I tested my RO/DI, salt mix and DT with similar widely varying results (table below).

Procedure:

1. Filled and emptied 6 vials with tap 10 times each. Dried with paper towel.
2. For each test:
   1. Filled and emptied syringe used for filling vial with test water 3 times.
   2. Filled and emptied vial with test water 10 times.
   3. Rinsed vial cap with 1 full syringe (20ml) of test water.
   4. Filled vial using syringe and capped.
   5. Dried outside vial with towel and wiped down with lint-free cloth.
   6. Put vial in tester and pressed button for C-1 (per instructions).
   7. Carefully added reagent after cutting along dotted line and folding as shown in instructions.
   8. Mixed reagent for 15 seconds per instructions. I do shake for about 10 seconds because at low readings that's the only way to get all the reagent to dissolve. But I then swirl for 5 and tap the vial to release bubbles.
   9. Wiped down vial with lent-free cloth again and put into tester.
   10. Wait 45 seconds for bubbles to settle per instructions.
   11. Close tester and press button for C-2 (per instructions).
   12. Read results

First test of RO/DI came up 0 -- good. The but the second test, with a different vial, came up 241. Two tests each of salt mix and DT weren't as dramatically different, but certainly more than can be explained by the +/- 10ppb accuracy stated on the instructions.

I was very careful to do all the tests the same except that they used different vials. So I re-washed 2 vials re-tested my RO/DI, two tests each, thoroughly washing the vials between tests and keeping track of which vial went with each test. The first vial got two 0 results -- good, I just hadn't washed my vials well enough. The third test (now with the other vial) came up 0 -- good, all going as expected. I re-washed that vial and did a second test with it -- 100ppb.

I give up. If I can't get consistent results when being as careful as I can possibly be, what good is this overpriced piece of rubbish?!?

Does anyone else have this problem? I see multiple reports that the HR Cu tester is unreliable at the low end. Is the same true for the LR checker, and might that explain my results?

I also double-checked and all my reagents are LR, not expired and from the same batch:

I'm not out of Cu LR reagent. I almost ordered more to keep testing, but I'm not sure I have faith in Hanna anymore and I'm reluctant to give them more money.

Here's my data:

Source	Cu (ppb)	Vial
RO/DI	0	A or B
RO/DI	241	A or B
Salt mix	71	C
Salt mix	28	D
DT	27	E
DT	0	F
RO/DI	0	A
RO/DI	0	A
RO/DI	0	B
RO/DI	100	B

 

[Idoc]

I believe my Hanna Cu tester is a high range one... didn't know they have a low range one actually!

But, I have had batches of reagent... mainly the ones that came with the tester... that were also giving very inconsistent results. Then opened a new box and the results were consistent.

Your technique seems sound to me.

 

[Randy Holmes-Farley Verified Community Expert]

This device appears unsuitable for low range copper measurement. it may be useful for medication levels, but it is not (IMO) useful to determine if copper is a problem in a reef tank. ignore the readings. Many folks get false high readings with it. It is, unfortunately, causing a lot of unnecessary angst amongst reefers.

 

[pseudorand]

This device appears unsuitable for low range copper measurement. it may be useful for medication levels, but it is not (IMO) useful to determine if copper is a problem in a reef tank. ignore the readings. Many folks get false high readings with it. It is, unfortunately, causing a lot of unnecessary angst amongst reefers.

Yup, I'd found your earlier post about that for the HR checker. But I'm using the Hanna LR Cu Checker, not the HR checker? Still think it's measurement error on the device?

If so, what should I use to check for copper toxicity? You are reported as having tested your tank at 15ppb, so presumably there's something out there? Or do I have to mail in a water sample?

 

[Randy Holmes-Farley Verified Community Expert]

I'm sure the variable results you got are measurement error. lol

 

[pseudorand]

Well, I want my $50+ back from Hanna then.

But more importantly, I want to know what's killing inverts in my QT?

 

[Shirak]

Have never seen that meter for salt water aquarium testing. Hanna only lists high range tester HI702 for aquariums. Info from Hanna
HI747
Range 0 to 999 ppb
Resolution 1 ppb
Accuracy @ 25°C/77°F ± 10 ppb ± 5% of reading

Are you trying to measure copper for a quarantine tank? You need to be between 2-2.5 ppm copper which this checker is not capable of.

As to why your readings are all over the place? ppb is really tiny amounts and that might have something to do with it. The only thing I see in your procedure is no mention you are placing the vial in the same alignment between testing the sample and after adding reagent. I have a small mark on my vials so I can orient the mark in the same position in the tester each time.

 

[Randy Holmes-Farley Verified Community Expert]

Are you trying to measure copper for a quarantine tank? You need to be between 2-2.5 ppm copper which this checker is

he is trying to see if low levels of copper are killing inverts in his QT.

 

[pseudorand]

Have never seen that meter for salt water aquarium testing. Hanna only lists high range tester HI702 for aquariums. Info from Hanna
HI747
Range 0 to 999 ppb
Resolution 1 ppb
Accuracy @ 25°C/77°F ± 10 ppb ± 5% of reading

Are you trying to measure copper for a quarantine tank? You need to be between 2-2.5 ppm copper which this checker is not capable of.

As to why your readings are all over the place? ppb is really tiny amounts and that might have something to do with it. The only thing I see in your procedure is no mention you are placing the vial in the same alignment between testing the sample and after adding reagent. I have a small mark on my vials so I can orient the mark in the same position in the tester each time.

The HI747 is their low range. The HR measures in ppm, not ppb.

I would try the vial rotation thing, but I'm out of reagent and reluctant to buy more since I don't think the meter does what it says.

I realize 2.5ppb is well within the advertised error range, but I wouldn't be concerned if it was flipping between 0 and 10ppb. I'm getting 200+ppb variance though.

And besides, no one has only 2.5ppb. see http://www.reefcentral.com/forums/showthread.php?t=2104096. If you think you do and you have water tests to prove it, please share what test kit your using to determine that.

 

[Randy Holmes-Farley Verified Community Expert]

And besides, no one has only 2.5ppb. see http://www.reefcentral.com/forums/showthread.php?t=2104096. If you think you do and you have water tests to prove it, please share what test kit your using to determine that.

Not a kit, but many people verify that they have less than that by ICP. My ICP showed less:

Triton claims a limit of detection for copper of 1.2 ppb (at least when I got my test) and they detected none in my tank.

My Triton Testing Results: By Randy Holmes-Farley - REEFEDITION

Recently, Triton GmbH in Germany has initiated a method of testing many ions at once for a single price. In the US, that service is coordinated by Unique Corals. For $49 they will send you a couple of tubes to collect a tank water sample, and a prepaid mailer to send the sample back to them...

www.reefedition.com

 

[Randy Holmes-Farley Verified Community Expert]

The HI747 is their low range. The HR measures in ppm, not ppb.

I would try the vial rotation thing, but I'm out of reagent and reluctant to buy more since I don't think the meter does what it says.

I realize 2.5ppb is well within the advertised error range, but I wouldn't be concerned if it was flipping between 0 and 10ppb. I'm getting 200+ppb variance though.

And besides, no one has only 2.5ppb. see http://www.reefcentral.com/forums/showthread.php?t=2104096. If you think you do and you have water tests to prove it, please share what test kit your using to determine that.

FWIW, copper bioavailability and toxicity is greatly reduced when it is bound by organics (as it is in the ocean or a reef tank, but not necessarily in a test.

i fought tooth and nail with Ron Shimek about this, and he finally "admitted; that copper in a reef tank is not nearly as toxic to his favorite organism to test (sea urchin larvae) as when he added the same amount of raw copper to a test sample and declared it a massive problem.

 

[pseudorand]

Not a kit, but many people verify that they have less than that by ICP. My ICP showed less:

Triton claims a limit of detection for copper of 1.2 ppb (at least when I got my test) and they detected none in my tank.

My Triton Testing Results: By Randy Holmes-Farley - REEFEDITION

Recently, Triton GmbH in Germany has initiated a method of testing many ions at once for a single price. In the US, that service is coordinated by Unique Corals. For $49 they will send you a couple of tubes to collect a tank water sample, and a prepaid mailer to send the sample back to them...

www.reefedition.com

So send in water is the only thing way. Not really practical or affordable for the change, test, iterate I need to do to verify if Cu is the problem in my QT, but I'll get my DT tested. That should hopefully rule out RO/DI failure and bad salt mix as sources if copper it is.

For the QT, I guess I'll just have to run cuprisorb and see if things survive. Sorry in advance to my next (and last) round of inverts. This is a cruel hobby, folks.

 

[pseudorand]

FWIW, copper bioavailability and toxicity is greatly reduced when it is bound by organics (as it is in the ocean or a reef tank, but not necessarily in a test.

i fought tooth and nail with Ron Shimek about this, and he finally "admitted; that copper in a reef tank is not nearly as toxic to his favorite organism to test (sea urchin larvae) as when he added the same amount of raw copper to a test sample and declared it a massive problem.

I just checked, and it looks like I did use Fritz coppersafe (2.2% chelated copper sulfate) when I mistakenly "murdered" my wrasses in this same (since cleaned) QT tank. Perhaps that's why deaths are mixed. Perhaps corals are better at dealing with chelated copper than crabs and snails. And supposedly cuprisorb removes the chealated stuff better, so I've got that going for me.

 

[Randy Holmes-Farley Verified Community Expert]

I just checked, and it looks like I did use Fritz coppersafe (2.2% chelated copper sulfate) when I mistakenly "murdered" my wrasses in this same (since cleaned) QT tank. Perhaps that's why deaths are mixed. Perhaps corals are better at dealing with chelated copper than crabs and snails. And supposedly cuprisorb removes the chealated stuff better, so I've got that going for me.

Crabs and snails are very sensititive to copper.

I'd replace the QT and everything in it, not keep trying to fix it.

 

[pseudorand]

Crabs and snails are very sensititive to copper.

I'd replace the QT and everything in it, not keep trying to fix it.

That doesn't help me if it's my RO/DI or mixing tub or salt mix. Or food. (I fed nori meant for humans. Supposedly just salt and seaweed, but...). I'd just end up contaminating a second set of equipment. I want to prove the cause and, if it's copper, identify the source. I've got still got living things and I can get cuprisorb in the tank faster than I can get a new one set up.

I'd also be inclined to do that if everything died. But my corals are alive. As is one astrea snail. He never even falls off the glass. And they're too small to find and count, but I only know for sure that one of my 10 hermits died. If it's copper, why are all those things still alive?

I did contact Hanna tech support to if there's variance in accuracy at the low range or based on type (chelated vs inorganic) of copper. I'll try to remember to post here if they reply.

 

[K7BMG]

Well good thread.
A few things I took note of.

1st washing vials in tap water.
I feel this is a no no, they should only be cleaned in RO/DI.
Or the proper cleaning solution.

2nd cross contamination of vials.
You said you have six vials. So you have 2 other Hanna checkers.
The two vials that came with the checker should be used with that checker. Clearly you are mixing and matching so who know what testing reagents were previously used and altering the results.
Even API test kits recomend to use the same vial for the same test.

3rd, yes you could have a checker issue but you have not, according to this post anyway contacted Hanna.
There suport was great when I had an issue.

 

[K7BMG]

Sorry you just posted that you are in contact with hanna.
Must have posted that when I was typing out my response.
So point three to be removed.

 

[pseudorand]

Crabs and snails are very sensititive to copper.

Also, I believe you, but is that just anecdotal or do you know of studies confirming the toxic levels of chelated copper for different sorts of reef inhabitants?

Not that I have any way to knowing how much Cu is in the tank at this point, but if I could be sure astrea snails are the most vulnerable, emerald crabs next and hermits and corals (at least the 9 types I have)
significantly less vulnerable, that would at least fit the available facts.

 

[Randy Holmes-Farley Verified Community Expert]

That doesn't help me if it's my RO/DI or mixing tub or salt mix. Or food. (I fed nori meant for humans. Supposedly just salt and seaweed, but...). I'd just end up contaminating a second set of equipment. I want to prove the cause and, if it's copper, identify the source. I've got still got living things and I can get cuprisorb in the tank faster than I can get a new one set up.

I'd also be inclined to do that if everything died. But my corals are alive. As is one astrea snail. He never even falls off the glass. And they're too small to find and count, but I only know for sure that one of my 10 hermits died. If it's copper, why are all those things still alive?

I did contact Hanna tech support to if there's variance in accuracy at the low range or based on type (chelated vs inorganic) of copper. I'll try to remember to post here if they reply.

Normal commercial salt mixes do not have enough copper to kill inverts.

RO/DI at 0 ppm TDS will not have enough copper to be any concern.

The mixing tub, if plastic, won't be adding copper unless you exposed it with copper you added.

IMO, there's no reason to not expect the obvious: you added copper to the QT and should expect it is no longer suitable for inverts.

I would not assume that corals as a suitable measure of copper for other organisms.

 

[Randy Holmes-Farley Verified Community Expert]

Also, I believe you, but is that just anecdotal or do you know of studies confirming the toxic levels of chelated copper for different sorts of reef inhabitants?

Not that I have any way to knowing how much Cu is in the tank at this point, but if I could be sure astrea snails are the most vulnerable, emerald crabs next and hermits and corals (at least the 9 types I have)
significantly less vulnerable, that would at least fit the available facts.

This database summarizes all published toxicity data for copper compounds. As you can see from just the crustaceans section, it can be very highly toxic with lethal doses below 50 ppb:

Ecotoxicity Summaries by Species

But you will not be able to make the simplistic assumption of what the best canary in the coal mine is.