COPPER the potential hidden killer in a reef tank
- Thread starter GrahamJr
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Running Cuprisol is good approach. If your losing snails your tank is telling your something is wrong. Snails love the bacteria that grows on the tank walls and on the live rock. The fact is you may well have been losing bacteria and reef pods plus various copods, in your tank well before losing the snails because the copper traces in the water was killing bacteria, which the coral and copods all use as a food source.
If you don't see a lot of copods and ocean pods in your tank you have an issue. The issue is low bacteria count which the pods need for food. One cause for this is copper which quickly wipes out bacteria….not the only reason this can happen though.
The DI cartridges used on RODI systems are mixed bed, so both cation and anion 
They are quite efficient at copper removal by themselves. I actually used the Aquarium Products Tap Water Purifier DI unit by itself on the tap water in old house with old leaching pipes. Straight out of the tap, the copper level was off the charts. After the DI, undetectable.
They are quite efficient at copper removal by themselves. I actually used the Aquarium Products Tap Water Purifier DI unit by itself on the tap water in old house with old leaching pipes. Straight out of the tap, the copper level was off the charts. After the DI, undetectable.The DI cartridges used on RODI systems are mixed bed, so both cation and anion
I fully agree and understand, but two comments"¦.1) it is easy to purchase bulk DI resin that is only Anionic, which does not remove copper. 2) at some point all DI resin is spent. If the cationic resin portion isn't changed out in a timely manner you will be adding copper. It doesn't take a lot of copper to poison and screw up a reef tank.
Yes it is plenty easy to buy either resin alone in bulk, but why would you get just one for our purposes? And yes, it does have a finite life span and need replacing, that's why we keep replacing those resins It's just another thing to keep up on for good maintenance. Doesn't matter what type of filtration set up your using, if you don't maintain it you will get burned.
It's just another thing to keep up on for good maintenance. Doesn't matter what type of filtration set up your using, if you don't maintain it you will get burned.
kzooreefer
New member
I too think you are over estimating how much copper will leach off copper pipe. You haven't even taken into account that over a very short period of time protective oxide and carbonate layers form over the pipe preventing corrosion. If it corroded at the rates you imply then it would have been dropped for use as piping long ago. The pipes in my home are over 30 years old and still going strong and I have no copper leaching off.
That very much depends on the water. If it's fairly alkaline, yes the corrosion rate will be low. However, if its soft and fairly acidic the corrosion rates will be high enough to be a problem for a reef and 30 year old piping will be prone to pin hole leaks popping up. A prime example is the plumbing in that old house I mentioned earlier
What Causes Copper Pipe to Leak?
What Causes Copper Pipe to Leak?
"What Causes Copper Pipe to Leak?
(pipe failure)
Contrary to popular belief copper water piping doesn't last forever. In its original design criteria, copper piping was projected to last for 20-25 years, but failure can often occur in as little as two years due to water chemistry.
Changes in water chemistry, unrelated to water quality, have caused the water to become aggressive towards the copper piping.
Copper is the most widely used material for plumbing systems because of its ease of use, resistance to corrosion, and resistance to permeation by liquids and gases, which may be sources of corrosion and contamination.
Copper piping has been used for domestic water supply for over 50 years. Since 1963, over 5.3 million miles of copper plumbing tube has been installed in about 80 percent of all U.S. buildings.
Hot or warm spots in the floor, soaked carpeting, ceilings or walls and abnormally high water bills are signs of failing copper pipes.
Pinhole Leaks
The State of Maryland Task Force to Study Pinhole Leaks in Copper Plumbing defines a copper pinhole leak as "the perforation of copper tube, pipe or fittings used for domestic water distribution as the result of pitting corrosion initiated on the interior/waterside surface with the subsequent leakage of water."
Internal pitting corrosion of copper pipes is a rare but costly problem that leads to the formation of pinhole leaks. Although the factors that cause this problem are mostly unknown, it is well recognized that the chemistry of the water traveling through the pipes can influence the formation and propagation of pits.
A pinhole leak is a final breakthrough event of the progressive attack of pitting corrosion on copper water plumbing. A copper water plumbing system can be in a condition of having significant damage by pitting corrosion, but not have pinhole leaks. The challenge is how to discover pitting corrosion before pinhole leaks develop.
Although pinhole leaks could happen in any copper pipe or tube within a house, the Washington Suburban Sanitary Commission (WSSC) reported that the majority of pinhole leaks that their customers had reported were in cold-water, horizontal copper piping. Most of the leaks were in older homes, and 80 percent of the reports involved homes built prior to 1970.
There is no comprehensive source of information on the occurrence of pinhole leaks. Many utilities and water authorities have collected thousands of reports, submitted voluntarily by residents who have experienced pinhole leaks. Often, homeowners consider pinhole leaks as a plumbing problem, and do not report them to their water utility.
Copper (Pitting) Corrosion
There are many forms of corrosion, but pitting corrosion is most likely to culminate in pinhole leaks in copper plumbing.
Pitting corrosion is the non-uniform localized attack of the wall of copper tube, pipe, or fittings initiated on the inside surface of copper water pipes. Usually only small areas of the metal surface are attacked.
Pitting corrosion can be classified into three types:
Type I
cause: Hard Water
Type I pitting is associated with hard or moderately hard waters with a pH between 7 and 7.8, and it is most likely to occur in cold water. The pitting is deep and narrow, and results in pipe failure.
Type II
cause: Soft Water
Type II pitting occurs only in certain soft waters, with a pH below 7.2 and occurs rarely in temperatures below 140° F. The pitting that occurs is narrower than in Type I, but still results in pipe failure.
Type III
cause: Cold, Soft Water High PH
Type III pitting occurs in cold soft waters having a pH above 8.0. It is a more generalized form of pitting, which tends to be wide and shallow and results in blue water, byproduct releases, or pipe blockage.
Water Velocity
When copper tubing is installed that is too small in diameter for the pressure and flow available, the resulting high flow rates can erode the protective coating creating areas of bare, unprotected copper. This effect can result in a high rate of corrosion wherever the protective coating is eroded.
The greatest effect of velocity occurs where the water is forced to change flow direction, such as at elbows and tees, but excessive water flow rates can be damaging to the entire plumbing system.
Repair Options
Currently, homeowners have several options from which to choose. However, none of the options address the root cause of the problem; they simply try to correct the symptoms. Most of the options are also costly. These options include:
Fixing the leak by application of external solder
Replacing a small or larger section of tube
Re-plumbing the entire house
(However, even a complete re-plumb with new copper tubing does not guarantee that the problem will not recur after a period of time.)
Re-plumbing and replacing copper with PVC or CPVC
Coat the inside of existing pipes with epoxy
Purchasing potential cures (of questionable value), such as magnets "
What Causes Copper Pipe to Leak?
"What Causes Copper Pipe to Leak?
(pipe failure)
Contrary to popular belief copper water piping doesn't last forever. In its original design criteria, copper piping was projected to last for 20-25 years, but failure can often occur in as little as two years due to water chemistry.
Changes in water chemistry, unrelated to water quality, have caused the water to become aggressive towards the copper piping.
Copper is the most widely used material for plumbing systems because of its ease of use, resistance to corrosion, and resistance to permeation by liquids and gases, which may be sources of corrosion and contamination.
Copper piping has been used for domestic water supply for over 50 years. Since 1963, over 5.3 million miles of copper plumbing tube has been installed in about 80 percent of all U.S. buildings.
Hot or warm spots in the floor, soaked carpeting, ceilings or walls and abnormally high water bills are signs of failing copper pipes.
Pinhole Leaks
The State of Maryland Task Force to Study Pinhole Leaks in Copper Plumbing defines a copper pinhole leak as "the perforation of copper tube, pipe or fittings used for domestic water distribution as the result of pitting corrosion initiated on the interior/waterside surface with the subsequent leakage of water."
Internal pitting corrosion of copper pipes is a rare but costly problem that leads to the formation of pinhole leaks. Although the factors that cause this problem are mostly unknown, it is well recognized that the chemistry of the water traveling through the pipes can influence the formation and propagation of pits.
A pinhole leak is a final breakthrough event of the progressive attack of pitting corrosion on copper water plumbing. A copper water plumbing system can be in a condition of having significant damage by pitting corrosion, but not have pinhole leaks. The challenge is how to discover pitting corrosion before pinhole leaks develop.
Although pinhole leaks could happen in any copper pipe or tube within a house, the Washington Suburban Sanitary Commission (WSSC) reported that the majority of pinhole leaks that their customers had reported were in cold-water, horizontal copper piping. Most of the leaks were in older homes, and 80 percent of the reports involved homes built prior to 1970.
There is no comprehensive source of information on the occurrence of pinhole leaks. Many utilities and water authorities have collected thousands of reports, submitted voluntarily by residents who have experienced pinhole leaks. Often, homeowners consider pinhole leaks as a plumbing problem, and do not report them to their water utility.
Copper (Pitting) Corrosion
There are many forms of corrosion, but pitting corrosion is most likely to culminate in pinhole leaks in copper plumbing.
Pitting corrosion is the non-uniform localized attack of the wall of copper tube, pipe, or fittings initiated on the inside surface of copper water pipes. Usually only small areas of the metal surface are attacked.
Pitting corrosion can be classified into three types:
Type I
cause: Hard Water
Type I pitting is associated with hard or moderately hard waters with a pH between 7 and 7.8, and it is most likely to occur in cold water. The pitting is deep and narrow, and results in pipe failure.
Type II
cause: Soft Water
Type II pitting occurs only in certain soft waters, with a pH below 7.2 and occurs rarely in temperatures below 140° F. The pitting that occurs is narrower than in Type I, but still results in pipe failure.
Type III
cause: Cold, Soft Water High PH
Type III pitting occurs in cold soft waters having a pH above 8.0. It is a more generalized form of pitting, which tends to be wide and shallow and results in blue water, byproduct releases, or pipe blockage.
Water Velocity
When copper tubing is installed that is too small in diameter for the pressure and flow available, the resulting high flow rates can erode the protective coating creating areas of bare, unprotected copper. This effect can result in a high rate of corrosion wherever the protective coating is eroded.
The greatest effect of velocity occurs where the water is forced to change flow direction, such as at elbows and tees, but excessive water flow rates can be damaging to the entire plumbing system.
Repair Options
Currently, homeowners have several options from which to choose. However, none of the options address the root cause of the problem; they simply try to correct the symptoms. Most of the options are also costly. These options include:
Fixing the leak by application of external solder
Replacing a small or larger section of tube
Re-plumbing the entire house
(However, even a complete re-plumb with new copper tubing does not guarantee that the problem will not recur after a period of time.)
Re-plumbing and replacing copper with PVC or CPVC
Coat the inside of existing pipes with epoxy
Purchasing potential cures (of questionable value), such as magnets "
disc1
-RT * ln(k)
They're based on chemistry. Copper in its 2+ oxidation state is a small cation with a pretty high charge density. That means it has a really high affinity for ion exchange resins.
The usual order of affinity for strong cation exchange is:
Hg2+ < Li+ < H+ < Na+ < K+ ≈ NH4+ < Cd2+ < Cs+ < Ag+ < Mn2+ < Mg2+ < Zn2+ < Cu2+ < Ni2+ < Co2+ < Ca2+ < Sr2+ < Pb2+ < Al3+ < Fe3+
Notice copper is right in the middle.
Now if people are putting only anion resin or are not maintaining their systems, I can't speak to that. That is a personal problem. But a properly functioning DI is going to pull out copper.
Source that from my Instrumental Analysis textbook.
disc1
-RT * ln(k)
You say that a RO/DI system will be only 99% effective at removing copper.
On what is that assertion based?
I'm saying that the left over copper after DI is several orders of magnitude less than 1%.
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nuccadoc
Member
Great discussion! It has brought to my attention that I do not use a DI resin, just RO. I wonder if my Seachem test kit can be used with fresh and salt water? I currently am not experiencing any problems with my tank inhabitants but I would like to know if I have any copper in my RO water.
"Applications Cation Resin Presented at the AESF Conference
Cation resins have very high selectivity for divalent cations, particularly copper and nickel. This makes them ideal candidates for the removal of various metals. This type of ion exchange resin has not been widely used by the surface finishing industry.
With respect to their resistance to fouling, weak acid cation resins are similar to other ion exchange resins. They are moderately resistant to oxidation, insoluble in solvents, and hydrophilic (water loving). Design limits for flow, pressure loss, temperature, bed depth, etc. are very similar to most other ion exchange polymers
A few weak acid cation systems have actually been operated at slightly more than 100% chemical efficiency (yes, this is possible under ideal conditions). However, most systems operate at 50-80% chemical efficiency due to foulants, precipitants, and short circuiting of flow that inevitably happens in any resin bed."
disc1
-RT * ln(k)
This link has an example of the math if you want to calculate it out.
http://purewaterlab.org/pwl_net/labs/D2_Process_Units/D2L3_Ion_Exchange/Equilibrium.html
http://purewaterlab.org/pwl_net/labs/D2_Process_Units/D2L3_Ion_Exchange/Equilibrium.html
disc1
-RT * ln(k)
And this one has the numbers you would need.
http://www.us.edu.pl/uniwersytet/jednostki/wydzialy/chemia/acta/ac15/zrodla/13_AC15.pdf
http://www.us.edu.pl/uniwersytet/jednostki/wydzialy/chemia/acta/ac15/zrodla/13_AC15.pdf
You've missed the point. No matter what resin you use they are all subject to reduced efficiency due to foulants, precipitants, and short circuiting of flow.
But to answer your question weak acid resin is more efficient at copper removal and easier to renew with a weak acid. Weak or strong resin has nothing to do with its effectivness in removing copper. It is the acid strength needed to renew it. Your SCX resin is more widely used in labs.
off topic: I hold 5 patents for controlling fluid flow in chemical processing. It isn't easy to do. Trust there is a lot of short circuiting in a little container of resin with saltwater flowing past it. It is not very uniform.
disc1
-RT * ln(k)
So you're saying there's no difference in binding kinetics between copper and carboxylic acids vs. sulfonic acids. I find that hard to believe.
The difference is the chemistry. They are two different beasts entirely. For one thing, WCX resins can't bind metals at low pH (<6 - 7). SCX can bind metals at any reasonable pH.
I think this topic as gotten a little off kilter.
I will try to restate my point. Small amounts of copper are very harmful in a reef tank. A natural reef has only parts per billion of copper.
Our drinking water systems, for a number of reasons can legally contain a thousand times more copper than you will see around a natural reef, and still pass EPA standards. Using DI filtration and cation resins normally removes most all of the copper, but there is always a risk of the DI cation resin system being less than 100% efficient for various reasons.
What I do, as an added insurance, to make sure copper does not get into my system, is run my RO/DI make up water over a bed of Cuprisorb before adding it to the tank In actuality, CupriSorb is nothing more than a weak acid cationic resin. You know that it is spent when it turns black and it can be renewed with a weak acid. In fact it could even be inserted into a refillable DI cartridge.
Cuprisorb has the additional advantage of being effective in both salt and fresh water. So if there is any question as to if you presently have excess copper in your reef tank, it can be added to a filter media bag and allowed to set in a high flow area to help remove ppb.
I would just assume you have too much copper in your system already, rather than try to test for ppb. The simpliest way is run a bag of Cuprisorb in the tank and filter your RO water through it. It can only help and will not harm.
nuccadoc
Member
I would just assume you have too much copper in your system already, rather than try to test for ppb. The simpliest way is run a bag of Cuprisorb in the tank and filter your RO water through it. It can only help and will not harm.
Yes, running Cuprisorb in my tanks would be good insurance. I would assume my RO water doesn't have copper in it because my TDS meter reads zero.
Just because you read zero on your TDS meter does not guarantee copper is not and will not be come an issue in your tank. TDS reads in ppm(parts per million). We are shooting for 1 to 5 ppb (parts per billion) one thousandth of what you are reading on your TDS meter.
Also remember we are talking a cumulative concentrating effect in a reef tank from water evaporation. You could easily start out with less the 5 ppb of copper and be well over 300 in a couple of years. Sitting and scratching your head as to why your coral are dying.
Copper in a fish-only system may safely run as high as 300 ppb, but a reef system should contain from less than 1 to 5 or 10 ppb Copper!
an aquatic system they can slowly accumulate to toxic levels
Most test kits cannot measure at these levels and if they do, their accuracy is dubious. Most Copper test truly measures total Copper, including that which may be chelated with citrate, EDTA, or other unnatural sequestering agents. Most kits provide free Copper concentrations only. This is a misleading measurement.
You can easily exceed the max 10 ppb of copper in a reef tank never even see a blip on the TDS meter from your make up water that you are adding daily.
The fastest indicator that you have a copper problem in your tank is if you can't keep crabs and snails alive very long. It's like carrying a canary into a mine.
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