Copper in a reef tank

[ReefTeacher]

I am seriously thinking of dosing Copper in my reef tank.

NOOOOO!!!!!!!:bounce2: IT"LL KILL EVERYTHING!

I hear you, and I understand. But this fall I started making some improvements to my tank. I use Triton testing to check for heavy metals. I had been away from SPS for a few years and would like to start adding them again. Triton detected no heavy metal problems in my tank, but several important metals were deficient: Mn, V, Zn, Ni, Mo. All I know are important to life. I have seen great improvement in my softies and LPS since dosing these elements.

BTW, I have a degree in chemistry. So I know how to make my own solutions.

I was remembering back to when I had a successful SPS tank around 2012. I used the Balling Methode Plus, (search for the website that contains "ReefDreams" in its name) which is a 3 part with added trace metals. It included all of the above plus some I am not dosing because Triton does not recommend them. But some in Germany have had great success adding the above trace elements as well as Fe, Cr, Co and Cu.

I know Randy's article on dosing iron, so I started with my own solution and have liked the results on my macroalgae.

So, reviewing old Chemistry texts, I see that Cu is biologically VERY important. According to a Reefkeeping article in 2005 seawater contains about 0.4 ppb Copper. IIRC Randy had about 10ppb Cu with no ill effects at one point. Triton says I have 0ppb. Given the LOD of 1.18-3.5 ppb. As long as I add small amounts and look for changes in the aquarium. I should be ok as long as Triton says I have 0 ppm. If they read one test with 5 ppb I would stop immediately.

So here is my thought. First run both Cuprisorb and a Polyfilter as insurance against overdose. This is like exporting nutrients and feeding the tank at the same time.

Next, using CuSO4*5H2O which is 25.2% Copper, make a solution which delivers 10 micrograms/mL Cu and dose daily. I have a 180 gal water volume so full strength seawater should contain 1.03 mg in the entire tank.

I might do the same with Chromium. I am cautious about dosing Cobalt, even though I had success before, as I now read that the normal seawater concentration is 0.006 micrograms/L very far below the LOD of Triton, so there is no real testing for this.

thoughts? Comments? am I crazy?

 

[pinnatus]

So first I will ask what is the sensitivity of your copper test? How low can it read? Low parts per billion readings are pretty hard to read unless you are using an ICP or similar.

I personally wouldn't want to mess around with it, unless you are willing to potentially lose all your inverts. Who is to say what is a lethal concentration, what is a problematic concentration, or what is the optimal concentration?

 

[ReefTeacher]

Pinnatus,

you go to the heart of the matter. I am NOT using a hobby test, I am using the Triton ICP-OES test which has an LOD of 1.18-3.5 ppb. Since people have tested even over 10 ppb without losing all their inverts, I think it would certainly be safe.

I realize that many would not want to mess with this, but I HAD added Copper as per the recipe I mentioned above in the Balling Methode Plus, but all trace elements were added in fixed amounts. What has changed in the last few years is the ability to test for individual elements. This way we have no need to dose the ones we don't want to.

And copper is necessary for life.

 

[pinnatus]

If you have the appropriate testing capability, which it sounds like you do, then by all means monitor and adjust levels appropriately.

Just wondering though, how you know what the appropriate levels should be?

Obviously some copper (and other metals) is OK, even good, but too much is bad. So where is the correct amount to control it at, what are the limits, and what is that based on?

 

[bertoni]

There's evidence that the Triton testing methodology is not accurate for trace elements. There's some reading available, if you're interested. Given that, I personally would avoid dosing copper into the system. I suspect that any food going into the system would have enough copper to keep the animals alive and well.

 

[pinnatus]

I will also say, that I do much prefer what you are doing than to blindly adding trace elements to the tank with no way to measure them. I would rather just do water changes than to do that. However, if you have the ability to reliably measure the levels and know what ranges to keep them in, then it makes perfect sense to control them by adding when needed.

 

[pinnatus]

For the average home reefer, it is not a financially viable way to keep parameters in range. An ICP is an expensive piece of equipment. Making up solutions with the appropriate chemicals is difficult and expensive, plus, sourcing the chemicals is difficult. Then you need to worry about the form of the chemical such as Iron (II) or Iron (III) and so on. The math involved is also beyond most home aquarists. Doing frequent water changes is a much more viable and foolproof method of keeping a reef "stable", in my opinion, for the vast majority of hobbyists.

 

[ReefTeacher]

Bertoni,

Do you have some references? I have done some reading of reviews and most of what I have found on Triton says that they read a bit high on Copper and Chromium. If there are additional sources you have I would like to take them into account too. Especially if the variance is such that it is not always an upper limit on the Copper concentration.

 

[ReefTeacher]

Making up solutions with the appropriate chemicals is difficult and expensive, plus, sourcing the chemicals is difficult. Then you need to worry about the form of the chemical such as Iron (II) or Iron (III) and so on. The math involved is also beyond most home aquarists. Doing frequent water changes is a much more viable and foolproof method of keeping a reef "stable", in my opinion, for the vast majority of hobbyists.

I have to disagree. But then I do have a degree in chemistry and I taught high school chemistry for about 20 years. I do not think math involved is beyond most high school graduates. It is especially not beyond most of the people who post on the chemistry board here at reef central. Anyway, I have the calculations in hand, even if they might frighten some.

I have sourced every substance I needed through either amazon or ebay...it is not in the least difficult; and it is VERY reasonable.

In terms of the chemical species (i.e. Iron (II) or Iron(III) ) what matters most is solubility. The ORP of the solution, and eventually the tank, will shift the equilibrium to the stable species. The proportion of Iron II to Iron III in my tank may well be different from yours, but it is little worth fighting about, as there is little we can do. Given the chelating agents in my tank vs. yours, an equilibrium will be reached and some ions will precipitate out, and others will be absorbed by chemical media. This is why I advocate frequent, small doses, and monthy ICP tests, to see where levels are.

But the math is by no means hard!

 

[bertoni]

This article covers the subject in some detail:

http://packedhead.net/2015/triton-lab-icp-oes-testing-of-a-certified-artificial-saltwater-standard/

 

[ReefTeacher]

This article covers the subject in some detail:

http://packedhead.net/2015/triton-lab-icp-oes-testing-of-a-certified-artificial-saltwater-standard/

Thanks so much for this. It was familiar, which means I had read it at one time. You will notice on the table at the end. He sent in a sample with 10ppb copper 3 times, and all 3 times Triton read high. My thought is that if I keep my triton results at 5 ppb or lower, I should be safe. For Chromium, I should read 0 at all times with Triton. But this article gives no help with Cobalt. Or should I say, Triton cannot detect Cobalt within any acceptable range.

 

[bertoni]

The copper might have read high each time he got a result, but I would not assume that the readings all will be high in the future. The accuracy was very poor, which is what I'd expect for such an inexpensive test, and I wouldn't trust the results, personally.

 

[pinnatus]

I have to disagree. But then I do have a degree in chemistry and I taught high school chemistry for about 20 years. I do not think math involved is beyond most high school graduates. It is especially not beyond most of the people who post on the chemistry board here at reef central. Anyway, I have the calculations in hand, even if they might frighten some.

I have sourced every substance I needed through either amazon or ebay...it is not in the least difficult; and it is VERY reasonable.

In terms of the chemical species (i.e. Iron (II) or Iron(III) ) what matters most is solubility. The ORP of the solution, and eventually the tank, will shift the equilibrium to the stable species. The proportion of Iron II to Iron III in my tank may well be different from yours, but it is little worth fighting about, as there is little we can do. Given the chelating agents in my tank vs. yours, an equilibrium will be reached and some ions will precipitate out, and others will be absorbed by chemical media. This is why I advocate frequent, small doses, and monthy ICP tests, to see where levels are.

But the math is by no means hard!

The math is not hard for you, or me either - I am a chemical engineer. But to the average hobbyist, it would be daunting. Like I said before, what you are proposing in an ideal world would be the preferred way of operating our tanks. Measure all parameters accurately, adjust accordingly and always have pristine, spot-on water.

However, after running chemical plants for the past 35 years, I know that measuring down to parts per billion levels and controlling within tight parameters is difficult at best. And there are always things that aren't measured that come up and bite you unexpectedly.

I say if you have the resources, the patience and the desire to do this, then by all means, it is a great approach. I am just saying that for the average hobbyist, simple water changes are a far easier, less expensive, and relatively fool-proof way to manage water chemistry. As a chemical engineer, I am all about cheap, easy and fool-proof.

You asked for opinions and whether or not you are crazy. My opinion is that no, you are not crazy. But I do think that what you want to attempt is difficult and expensive. Just as an example, controlling hardness in these tanks is a difficult task, due to the relationships between calcium, magnesium, pH, etc. Controlling all the parameters in the ionic soup that is salt water is going to be a difficult task.