COPPER the potential hidden killer in a reef tank

[billsreef]

Excellent points. Two things you are not considering.

Your assuming here

1) The continually increasing copper concentration from evaporation if our make water contains more copper than is acceptable to the organisms.

Now this works if the make up water does indeed have more copper than is acceptable to our organisms. If it make up water has low enough levels to be acceptable to our organisms, than it's a non issue.

2) If the excess copper is being bound in the live rock, substrate, and the organisms; what will happen if a pH or temperature swing, or other flux, causes the copper to go back into the water column in a higher concentration.

This can be a problem if there is excess copper in the water. In the levels were talking about being able to past a well maintained RODI system, it's a non issue IME.

This has always been the discussion around the detrimental effects of phosphate bound up in the live rock and substrate, and a potential cause rapid death in established reef tanks.

Somewhat different chemistry going on here, as well the levels involved. Also the idea of phosphate causing rapid death is still in the realm of opinion. IMO phosphate problems in a tank are long time building...far from rapid, though the unobservant might miss all the warning signs and think the results are rapid.

Curious as to what you propose to do about the copper that may enter through the salt mix, food and other items imported into the aquarium as well as the other metals that may or may not be imorted or make it past the RO/DI stages that your concern outlines?

Indeed, salt mix and food are going to be the largest inputs of copper if one is using a well maintained RODI system for their fresh water source. With the phosphates you mentioned, that also holds true.

 

[disc1]

what will happen if a pH or temperature swing, or other flux, causes the copper to go back into the water column in a higher concentration.
.

If your pH goes below 7 (to get copper hydroxide and carbonate back into solution) then you've got way bigger problems than copper.

 

[jimsplace]

Man, to quote an old song; paranoia strikes deep ....

 

[GrahamJr]

Curious as to what you propose to do about the copper that may enter through the salt mix, food and other items imported into the aquarium as well as the other metals that may or may not be imorted or make it past the RO/DI stages that your concern outlines?

Excellent point"¦.this probably why you see more amd more in tank filter media on the market and being used on a regular basis inside the reef tank"¦like it is recommended in using Cuprisorb.

This whole topic was to bring to the attention of many new reef keepers the potentially extremely high copper found in home water systems today and the potential danger. Much of it due to the changing waster chemistry used to purify our drinking water, and the very high EPA allowable thresholds in the US. It also touched on the danger of even higher copper content in many home water systems due to copper pipe corrosion caused by stray electrical currents. If steps are not taken to remove the copper in the water you put into reef tank, which could easily be several thousand times the amount of copper seen in a natural reef.

There are many new reef keepers that will never have a chance to develop that beautiful reef tank they dreamed about if they do not address the issue, that they often don't even know they have. Similar to treating for chlorine, when your water plant is injecting chloramines.

Like many threads on RC, members often enjoy getting off topic and arguing how high is up.

 

[disc1]

Parts per billion of copper will not even get through a spent DI filter because of its high affinity. Great theory and has merit. I think that would be a very interesting experiment for you to run. Let me know the outcome. Until then, I'll keep polishing.

Actually, I can go one better even. In quantitative analysis lab one of the common experiments while learning about ion exchange chromatography is to have the students analyse a mixture of zinc and nickel. The solutions have to be concentrated, and this is done over a SCX resin.

Now zinc has a lower affinity for sulfonic acid resin than does copper. If I can quatitatively concentrate zinc over SCX resin, then what would make me think I can't do the same with copper?

So there. Experiment done a thousand times over with an even more difficult ion.

 

[Yogre]

Curious as to what you propose to do about the copper that may enter through the salt mix, food and other items imported into the aquarium as well as the other metals that may or may not be imorted or make it past the RO/DI stages that your concern outlines?

This is my concern as well, and why I'm thinking of running Cuprisorb on at least a part time basis on my tank. Will I be able to tell any difference without an expensive instrumental analysis for Cu? Maybe not, but what the hey it couldn't hurt.

 

[BeanAnimal]

But it does cost

 

[disc1]

Let's put some math on the build-up in the tank too while we're at it.

We'll use GrahamJr's numbers, just for argument sake. I say they're inflated, but whatever. This can represent worst case scenario.

So if we say that RO can take out 99% and then DI can remove another 90%, that makes our math easy at a 3 log reduction. So 1ppm in the tap becomes 1ppb in the filtered water.

SO let's use water for changes and make-up that has 1ppb copper.

Let's assume a 100L tank (to round the math off easy, our calculation can be scaled to any size). That's almost 40ga so let's go big and give it 3 gallons of top off per week.

A ten percent water change is 10L, which at 1ppb contains 10ug of copper.
The three gallons of top off bring another 11.4ug.

So we are adding 21.4ug of copper to the tank per week.


Equilibrium will be reached when we are removing as much as we are adding. That's going to be the ten Liter water changes. If 10 Liters out is 21.4ug, then the concentration in the tank is 2.14ppb.

So if it really is as bad as you say, and DI can only get it down to 1ppb. The steady state in the tank would still only be 2.14ppb. That's as high as it's going to go. At that point, your water changes take out as much as the water change in plus the top-off.

It can't just climb forever. The math doesn't work that way.

 

[disc1]

Curious as to what you propose to do about the copper that may enter through the salt mix, food and other items imported into the aquarium as well as the other metals that may or may not be imorted or make it past the RO/DI stages that your concern outlines?

I know it hasn't been totally proven, but I am a firm believer that heavy metals are the root of Old Tank Syndrome. At some point it has to start cutting down the biodiversity, which I think sits at the root of all of the other causes that are put forth. But that's just my opinion.


Check out this link. http://andrew.ucsd.edu/courses/sio263/downloads/brulandlohan-tog2003.pdf

It's got a great table of all the elements smaller than lead in seawater with distributions and mean concentrations. It's a logarithmic scale. So be careful with the graph...


According to it, the mean concentration of copper in the ocean is somewhere around 4 nmol / kg. That's 254ng / kg or 0.254ppb.


Some of our salt mixes start out higher than that. And our DI water does have copper in it, although it is parts per trillion and not parts per billion.

When you add those two things together and do the same math as my last post, you come out to an equilibrium concentration that can be above 1 ppb. But it is mostly from the salt and not the water.

Copper is not soluble in basic solutions or solutions with carbonate. If you want to see for yourself, mix a solution of copper sulfate with some salt water and watch the blue precipitate that forms. With the medications we use, they are using chemistry to hold the copper in solution. This same chemistry happens to some extent naturally in our tank. Search the word chelate if you want more.

Since copper (II) carbonate is insoluble, it is easy for copper to precipitate out with calcium carbonate. This is the reason they tell you to leave the kalk crud in the ATO bucket when you dose kalk. The super basic conditions, and available calcium carbonate (From Ca(OH)2 + CO2) to precipitate on, will pull any copper or other heavy metals out of the water or the kalk. They say that the crud in the ATO purifies the kalk.

So in the tank, the copper can precipitate out into the substrate and the rock. GrahamJr is right, with a low enough pH you can redissolve it. But if pH goes that low or temp that high then you've got way bigger problems than copper. The calcium carbonate that makes up the rocks will dissolve before the copper carbonate does.

The problem IMHO is bio-accumulation of the copper. Bacteria and pods, all the way up the food chain in your tank. Eventually, I believe that leads to the OTS. Again that statement is just opinion, but informed opinion I believe. There are a lot of other things too that build up in your substrate and rocks over time. But I think the tiny closed food chain is to blame. A short search on ecology and bio-accumulation should give you plenty to read on how poison moves up the food chain.

There is no black dark chasm of the deep for biomass to disappear into in your tank like there is in the ocean. Eventually, the copper we add into the ocean will be in the crude oil. If only we could be so lucky with our tanks.

 

[Yogre]

But it does cost

True dat. I should have said it won't hurt anything but my wallet. :lol:

I'll try it for a while. I'm pretty cheap, and if I can't see any change, which I may well not, I'll quit. I'll just be out the cost of a half liter of Cuprisorb. Granted I'll be out the cost of a decent Scotch but hey ya only live once, right?

 

[GrahamJr]

What is the saying David....Torture numbers, and they'll confess to anything.

If you will bear with me, lets look at real life numbers.

Take as an example my reef tank. Not very large, it only holds approx. 50 gal.of water/with the live rock.

Through evaporative cooling, I add two gallons of make up water every day, or 1/25th of the tank water volume. I know this is fairly accurate because I fill my 5 gal. make up water tank manually every day with two gallons of RO/DI water. I used to me much a much higher evaporation rate when I used HID lighting, but I've changed over to LED and greatly reduced the heat input.

Now for arguments sake, again bear with me. Let us use some very real and published numbers. First, let's assume the reef tank hobbyist home copper water system is lousy and it exceeds the EPA 1.3 ppm copper limit, which the EPA says over 10% of the homes often do, so again for arguments sake lets assume the raw water actually contains up to 2 ppm of copper. Not a major change and an easier rounded number to demonstrate. Keep in mind I'm only demonstrating a very real possibity. I am not saying everyone has these issues.

Also, let's use the numbers Reef Central publishes, for RO membranes as being 90% to 98% efficiency. Again, only for arguments sake, lets assume on RO membrane has been damage by chlorine or chloramine and is only running on the low end or 90% removal. Not really too outlandish of an assumption so far....agree?. (http://www.reefcentral.com/index.php/rodi-faq).

Again as an example: That means nuccadoc, who has commented on this tread, saying that he has only been using an RO system and no DI, believing because his TDS meter was reading zero he isn't putting copper into his tank. But, in actuality he could be putting 180 ppb of copper into his tank with every gallon of water he uses for make up or water changes. (2ppm x 90%) Still with me? If he has questionable water quality, he sure needs to add a DI system onto his RO......

Now lets look at my own case...I do use RO/DI. So let's assume, again for argument sake, and use your 90% efficiency number for DI resin. As I explained earlier, I do not think that to be to far off, based on my personal observation of two DI cartridges hooked up in series, and how they clearly indicate short circuiting and bypass is taking place.

That 180 ppb of copper is now reduced 90% to 18 ppb in every gallon of makeup water after going through DI......right?

Now here is where it starts to get interesting. Lets get back to my 2 gallons of daily make up water. Every 25 days I am virtually replacing all the water in my tank from evaporation cooling. But, because the minerals and heavy metal didn't evaporate, including the copper we are talking about. That means the 18 ppb of copper in my newly filled tank, becomes 36 ppb in 25 days. Or to look at it another way, over one year my copper could increased 250 ppb . Now, I don't think all of that copper will show up in a water column test, because much will be deposited into the tank sediment and live rock.

Now I know you will argue next, if you did monthly water changes of let's say 10% per month, all of that copper will be diluted and removed....well lets look at the facts. First, a lot of reef keepers don't always even do water changes after awhile, but for argument sake let's say they are.

As you can see in the chart above, if you did 10% monthly water changes it would dilute the water, but by less than 60% at the end of a year since you are still adding make up water that starts out with 18 ppb of copper. Or to put it another way, you are potentially building up copper at a rate of over 100 ppb per year. Now also keep in mind, this copper isn't necessarily staying in suspension. A lot of it may be working it's way into the biological system

I think your comments about copper precipitation is in kalk is very interesting and could be correct, but the problem is you are making assumptions that every one uses a kalk reactor. I do, but I know many reef keepers that do not. Also when I do my regular 10% water changes it doesn't get filtered thru kalk first. Also keep in mind there is still a lot of open discussion on low pH occurring under anaerobic conditions in deep sand beds and inside live rock, so do not assume copper and other heavy metals cannot be put back into solution under the right conditions.

I firmly believe too much heavy metal, especially copper, and the tank will be slowly poisoned. It could be a very slow painful death. It could it be one of the causes of what people call Old Tank Syndrome you mentioned, possible. First the bacteria population declines, then other microscopic animals feeding on the bacteria decline, snails, and crabs die off, live rock and live sand decline, the coral slows and coral starts dying off, and after a few years of doing that and I think you will find one very frustrated and unhappy reef keeper. Quoting your comments below...you seem to agree with me.

And you paraphrased Ron Shimek's theories very well......" I am a firm believer that heavy metals are the root of Old Tank Syndrome. At some point it has to start cutting down the biodiversity, which I think sits at the root of all of the other causes that are put forth. But that's just my opinion. "œ

When I read what you are saying, it seems like you are sometimes arguing both sides. You appear very knowledgeable on reef keeping. I'd love to see a photo of your tank, privately if you like, to see how you've put theses theories to work in your own reef tank and learn more about your system.

 

[jeff@zina.com]

The fact is my second DI(2) starts to show some indicating color change soon after being installed, and it is indicating considerable color change well before the first DI(1) is indicating only 50% spent. The only way this could happen is from internal fluid short circuiting within in the first DI(1) or a lower than 100% capture efficiency of the new resin.

There are two issues here. The first is that color changing DI is notoriously wrong. Colors can change too fast, too slow or not at all. The second issue is that a second DI does take over after the first is used, but it's hard to tell exactly when the first is used.

There's not normally a way for liquid to get past the DI in a normal setup. But it's possiblt the DI isn't fully processing the water. That's another experiment that needs to be run in a controlled environment.

Jeff

 

[disc1]

GrahamJr,


Your story here seems to revolve around the lazy aquarist who doesn't do water changes and allows their RO/DI to crap out.

Yes, I agree 100% that guy is in trouble. But he's in trouble for a lot of better reasons than copper long before the copper gets him. Yes, you're absolutely right. If you don't take care of your tank, it is doomed.

 

[disc1]

This short circuit thing is not right either. Short circuit isn't a good word for it. What you mean is channeling. Some of the water finds a way through the resin without making any contact. You want that to mean it comes through unchanged. That's just not true. You are completely ignoring diffusion. Unless you are blasting the water through the DI resin at light speed, then diffusion is something you cannot ignore. The flow in the DI chamber is not laminar. Not even close.


The fact that your color changing resin in your second chamber changes means nothing. That doesn't indicate the presence of copper. In order for copper to make it that far, the entire first stage would have to be full of nothing but copper and ions with a higher affinity for the resin than copper. By that point, there would be enough sodium and other low affinity ions passing through the resin to raise your TDS level to a noticeable level.

You can't ignore chemistry here. That is all this is about. If your DI resin is only 90% effective at removing copper then it is only about 1% effective at removing sodium. I think you would notice that.


Yes I know that copper is bad for your tank. Did you think you were making some new revelation here? We've known that for a long time. It's nothing new. But the major source of that copper is not your water if you have a good RODI. The major source of copper is the salt mix and the food.

 

[GrahamJr]

GrahamJr,


Your story here seems to revolve around the lazy aquarist who doesn't do water changes and allows their RO/DI to crap out.

Yes, I agree 100% that guy is in trouble. But he's in trouble for a lot of better reasons than copper long before the copper gets him. Yes, you're absolutely right. If you don't take care of your tank, it is doomed.

I don't believe you even bothered to read what I wrote. My explanation had absolutley nothing to do with a lazy aquarist. Are you insinuating I'm a lazy aquarist"¦not very nice.

I took the time a few minutes ago to look at the photos of your tank published in your profile"¦..they are about six months old. Do you have any new up todate photos?

Attached below is a photo of a lazy aquarists tank"¦my tank.

During our discussions, which you have helped stimulated my thinking so well, could it be that one reason ZEO System users are so successful is that they use zeolite as a media on which to stimulate bacteria growth. It is interesting that zeolite also has a high affinity for copper/lead and is one of the best copper removal medias? Another topic and an interesting thought to mull over!

 

[disc1]

The age or beauty of my tank has nothing to do with it. Yes, I recently set the tank back up.

But the question of how much copper can make it through a DI resin isn't a fish keeping question. That's a chemistry question. And when it comes to chemistry I think I have the background to answer it.

 

[disc1]

Just because you don't understand chemistry, doesn't mean you can ignore it.

 

[GrahamJr]

Just because you don't understand chemistry, doesn't mean you can ignore it.

Dave,

I really don't think it benefits this thread to carry on this dialogue any further"¦.you are getting increasingly more and more contentious.

 

[disc1]

If there's 20ppb of copper making it through the RODI, then explain to me why the 20ppm of sodium that would come with it won't show up in my TDS meter.

 

[disc1]

Dave,

I really don't think it benefits this thread to carry on this dialogue any further"¦.you are getting increasingly more and more contentious.

I'm merely trying to keep things factual.