Hanna LR Cu unreliable

[pseudorand]

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.

That's why r2r is great. Expert advice in real time. (We're all such reef nerds!)

I also just contacted their marketing department to suggest:

• Test vial cleaner (I'd pay for that, but I may try to engineer one myself with a funnel and some hoses. I'll post in the DIY forum if I do.)
• Marked test vials to avoid mixing them up between test kits
• Notches on the vials and checkers to make sure they're aligned the same between the calibration and test phases.

 

[pseudorand]

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.

Okay, I get it. Biology is hard, complicated and necessarily inexact. But I'm from the computer industry where attempting to solve problems you don't know the root cause of doesn't generally go well.

 

[schuby]

Not to beat a dead horse, but as @Shirak alluded, a QT target of 2-2.5 ppm of copper is 2,000 - 2,500 ppb of copper. That range is far above the range of your checker. Looking at your results, the highest test result was 0.241 ppm.

You might also consider that your tap-water rinse may be leaving a residue that affects your results. Maybe consider rinsing vials, caps, and syringes with distilled water: your checker is very sensitive.

 

[K7BMG]

Okay, I get it. Biology is hard, complicated and necessarily inexact. But I'm from the computer industry where attempting to solve problems you don't know the root cause of doesn't generally go well.

WHAT computers are perfect.
ROTFL.

 

[Randy Holmes-Farley Verified Community Expert]

Okay, I get it. Biology is hard, complicated and necessarily inexact. But I'm from the computer industry where attempting to solve problems you don't know the root cause of doesn't generally go well.

Welcome to reefkeeping problem solving. lol

 

[pseudorand]

WHAT computers are perfect.
ROTFL.

None. That's why I'm employed. Or more correctly, the people who tell them what to do (including me) are imperfect. But they're orders of magnitude simpler than biology, so if you know what your doing you can be sure of what the problem is before mucking with it and verify your fix worked right away. In this situation, I have to guess that Cu is the problem, and even if it doesn't reoccur with all new equipment, I'll never be completely sure it was. (i.e. the snails could have died because there was no algae to eat in the tank yet and they didn't like my nori, and the crab could have been sick before I got him.)

 

[Shirak]

In this situation, I have to guess that Cu is the problem, and even if it doesn't reoccur with all new equipment, I'll never be completely sure it was. (i.e. the snails could have died because there was no algae to eat in the tank yet and they didn't like my nori, and the crab could have been sick before I got him.)

Do you check salinity of the water after arrival? I have found snails very sensitive to salinity changes. Particularly when going from a low salinity from the LFS of 1.018-20 to my reef up around 1.027. I have to acclimate them slowly or they just shrivel up and die.

 

[pseudorand]

Hum. That could be too. I do have the QT at 1.027. But I did drip acclimate for at least half an hour, and they lived for a week after that.

 

[pseudorand]

Hanna got back to me in 1 business day. The LR Cu checker hasn't been validated for seawater. No where do I see that on the product page or the manual (please correct me if I'm wrong on that). I'm still disappointed with Hanna. Seems that should be listed prominently on the page somewhere.

 

[pseudorand]

I just realized that in the table in my original post, I tested RO/DI water and got widely varying results.

I've bought a aqualifter (I need a spare on hand for my overflow anyway) to implement my DIY test-tube cleaner (it was too hard to get the right pressure with gravity-driven). I'm going to re-test my RO/DI with extra care and complain to Hanna if I can't even get consistent results on freshwater. It will probably just end up being testing error on my part though.

 

[pseudorand]

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.

As usual, you rock Mr. Holmes-Farley. Thank you.

Looks like ug/l == ppb, and various types of crabs are both some of the most and least sensitive, and no Mithraculus (Emerald crab genus) on the list, so no help there. I also don't see any snails, but I'll vote to add a row with some now LC50.

Now, if only I'd paid $50+ for a scientific instrument that could measure copper concentration...

 

[pseudorand]

I just realized that in the table in my original post, I tested RO/DI water and got widely varying results.

I've bought a aqualifter (I need a spare on hand for my overflow anyway) to implement my DIY test-tube cleaner (it was too hard to get the right pressure with gravity-driven). I'm going to re-test my RO/DI with extra care and complain to Hanna if I can't even get consistent results on freshwater. It will probably just end up being testing error on my part though.

The aqualifter works great to clean test tubes with RO/DI. I go from a 5-gallon bucket on a table to another 5-gallon on the floor and use a power strip to turn it on and off. I also needed some 1/16" rigid pipe because airline tubing is big enough to block the opening, at least of a Hanna test tube. (I had some from an old under-gravel filter.) I still rinse with tap first to avoid putting test chemicals in any bucket I may mistakenly use for a tank. I have to clean test tubes one at a time, rather than the 10-at-once I'd imagined in my overly-complicated gravity-fed DIY solution, but that's all the Aqualifter is powerful enough for anyway.

 

[nkarisny]

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.

yes i went from .13 10 .10 after dosing 6 tsp copper aid then dosed another tsp and get .10 . how did i go down .

 

[Randy Holmes-Farley Verified Community Expert]

yes i went from .13 10 .10 after dosing 6 tsp copper aid then dosed another tsp and get .10 . how did i go down .

IMO, those values are all in the noise of the test result. Don't over interpret small changes just because it is digital.