COPPER the potential hidden killer in a reef tank

[GrahamJr]

Quote:
Originally Posted by EnderG60
"no copper has ever or will ever be anywhere near this tank."


"Copper tubing remains the most widely used home plumbing material among homebuilders and homeowners. Professional installation or some plumbing knowledge is usually needed, as the use of soldering compounds or compression fittings is necessary to join the various sections of pipe.
In situations where the pH of the water is below 6.5, there is the potential for copper to leach from the pipe into drinking water above allowable levels."

There is a very good chance your home has copper piping for drinking water, most do. The potential for a very slow but deadly build up of copper in a reef tank is very real from copper leaching. What is considered the EPA allowable safe drinking level is 1.3 PPM (parts per million), but for a reef tank it is measured in PPB (parts per billion), a thousand times less.

Often the electrical system in a home is often grounded to copper piping. Stray currents or shorts can easily cause galvanic action and leach copper ions into your water. Also copper buried in the ground can see stray ground currents that cause the copper pipes to corrode. A corroding copper pipe is leaching copper into your drinking water and the water you may well be using for the reef tank.

In one area in Florida that I am familiar with the homes, they have so much natural stray ground current, that their waste water even exceeds the allowable EPA limit for copper in the waste going to waste treatment plant. It is due to the copper leaching inside the homes buried copper water system. A sure killer for a reef tank.

Something worth considering as an issue and maybe your problem.
I filter all my RO water through copper removal media because of this concern.

I am going to post this as a new topic. I think it is important information to realize and consider if you are in the hobby.

 

[jimsplace]

I may be wrong, but I thought the ro/di removed copper. I have copper water pipes in my house and have kept a reef for 15 years with no problems and have always used water from my ro/di unit.

 

[disc1]

That's one of the main reasons people preach so much about using RODI to purify your water.

I wonder if you could use zinc to prevent the unwanted corrosion of copper pipes.

 

[disc1]

That's one of the main reasons people preach so much about using RODI to purify your water.

I wonder if you could use zinc to prevent the unwanted corrosion of copper pipes.

 

[GrahamJr]

I did not mean to imply that just because you have copper piping that you will have copper issues. I am saying it is a potential issue, especially over time as it is absorbed into the live rock and substrate, building up in concentration.

Copper leaching from piping is highly dependent on many factors. The water pH, stray ground currents, electrical equipment issues, and you home electrical system all come into play. Actually RO water is highly corrosive to copper, and could be an issue if it comes in contact with copper down stream of the RO unit. If someone has a permanent RO set up and uses copper down stream it is an issue. Also copper is not fully removed by RO which is why Carbon is also used in series. Permeate flux, conductivity, pH, and copper concentration of the permeate are measured to determine the membrane characteristic and rejection.

 

[disc1]

Copper is not completely removed by RO, that's why you need a DI stage. DI will clear it all out. Never put copper fittings downstream of your RODI.

 

[kzooreefer]

I did not mean to imply that just because you have copper piping that you will have copper issues. I am saying it is a potential issue, especially over time as it is absorbed into the live rock and substrate, building up in concentration.

Copper leaching from piping is highly dependent on many factors. The water pH, stray ground currents, electrical equipment issues, and you home electrical system all come into play. Actually RO water is highly corrosive to copper, and could be an issue if it comes in contact with copper down stream of the RO unit. If someone has a permanent RO set up and uses copper down stream it is an issue. Also copper is not fully removed by RO which is why Carbon is also used in series. Permeate flux, conductivity, pH, and copper concentration of the permeate are measured to determine the membrane characteristic and rejection.

I've never seen a carbon of any type that could remove copper or any other metal from water, and I've worked in the water processing field for over 15 years. The RO system alone is sufficient to remove copper and when used in conjunction with DI resin it is more than effective. There is very little chance of copper coming in contact with RO water as it is stored in a tank in most instances and fed to a tap by plastic tubing. The taps themselves are nickle plated or stainless steel, no copper involved, there maybe some brass fitings but these do not come in contact with the water. Like a lot of people here will say they've used these systems for years without problems. A lot of people like to blame copper for tank crashes just because they can't find any thing else to blame. The only times I've seen or heard of copper actually entering a system has been when a heater cracked or pump developed a leak and the copper wiring corroded. I've also heard of people using old tanks that had one time been dosed with a copper medication leaching copper out of the silicone. Those would be of greater concern to me than copper getting past an RO membrane.

One thing I have to add in your favor is that if the membranes are old and the DI cartrdige depleted and you get a person who isn't diligent in changing them out frequently then you could have an issue, very slight but still could happen I guess.

 

[billsreef]

That's one of the main reasons people preach so much about using RODI to purify your water.

I wonder if you could use zinc to prevent the unwanted corrosion of copper pipes.

Zinc is also toxic to reef critters

 

[disc1]

Zinc is also toxic to reef critters

Oh no, I meant zinc on the outside of the pipes. Kinda like how you use it in a boat.

The zinc has a lower reduction potential so the copper can't corrode until the zinc it is in contact with does first. They don't even have to be in physical contact. They just need to be connected electrically.

I know zinc will serve for iron, and copper is the more "Noble" metal, so it makes sense. I'd have to go look up the reduction potentials.

 

[disc1]

Yeah.

Cu2+ +2e- -> Cu(s) is 0.339V
Zn2+ +2e- -> Zn(s) is -0.762V

So zinc should protect copper.


I thought that reaction went that way. Isn't that how you run a clock off a potato?

 

[billsreef]

Oh no, I meant zinc on the outside of the pipes. Kinda like how you use it in a boat.

Won't do a thing to prevent corrosion from outside of the pipe. It also won't do a thing for your boat if it's above the waterline

 

[billsreef]

BTW, it's the water that makes the circuit for electrolysis...aka the sort of corrosion that zinc is used for.

 

[disc1]

BTW, it's the water that makes the circuit for electrolysis...aka the sort of corrosion that zinc is used for.

Or dirt.

I thought I had heard of it being done with old cast iron pipes. You bury the zinc and connect it to the pipe. The zinc corrodes in the ground and keeps the potential too low on the iron for it to corrode. The dirt provides the high impedance path to close the circuit. Basically you make a battery.

 

[disc1]

Here's a halfway decent tutorial on the concept found via Google.

http://www.sescocp.com/tutorial.php

http://www.bushman.cc/pdf/corrosion_theory.pdf

 

[disc1]

Still, I see what you mean, it only protects the underground pipes.

 

[edsreef]

Funny this topic came up. I just ordered some Cuprisorb to use as an occaisional preventative measure to ensure against the potential of unwanted heavy metal buildup over time. I don't know that I have any copper in my tank but thought it was a wise move to prevent a future crash caused by some unknown.

 

[GrahamJr]

I've never seen a carbon of any type that could remove copper or any other metal from water, and I've worked in the water processing field for over 15 years. The RO system alone is sufficient to remove copper and when used in conjunction with DI resin it is more than effective. ...................

I should have said DI in series, I stand corrected on the carbon. But, I stand by my basic premise regarding the dangers of excess copper building up in our reef tanks, dangerous levels to coral, which can develop from copper pipes in a home water system.

It is true RO and DI ( if the proper DI resin is selected) remove copper. Up to 99 to 98% removal, if you keep an efficient RO membrane. The EPA allows up to 1.3 ppm of copper in drinking water as being safe for humans, even thought 1.3 ppm is 10 times what is allowed in Europe. The fact still remains, even if you run the numbers using 98-99% removal, that still leaves a potential of 1 to 2% percent copper after the RO/DI system. Copper around natural reefs is measured in ppbillion, which means even with 99% removal of copper you can still very easily be introducing ten times the amount of copper measured in natural reef water.

And that is not taking into consideration the point I was making with my comments on how much higher than 1.3 ppm can easily be exceeded in a home, that may have electrical grounding issues and/or even water softening issues, which will allow much higher concentrations of copper to develop in the home water system. True everyone isn't subject to the same potential issues that can cause an excess copper problem. And I totally agree, most will never see a problem when doing regular RO membranes and fresh DI resin changes, and 10% water changes per week.

The fact is, most reef tank keepers do not do a high enough percentage of regular water changes, even at 10% a week, to keep a copper concentration from slowly increasing over time and building up in the live rock and substrate, even if they only had 1% of the allowable EPA copper allowance getting past the RO/DI system. If they do have an issue.

Based on the assumption about 1/50th of your water evaporates per day, and you will almost double the concentration of what ever bad stuff you have in your tank per month; I still feel it is too high a risk to be ignored or to feel safe just because you are using an RO/DI system. Plus many do not always change out RO/DI filters and media until they see a problem.

My neighbor just had couple of copper water pipes corrode and burst in his garage last year, so I know my water system copper content is in question. Personally, I will continue to use cuprisorb resin to filter copper out of my RO/DI makeup water to be safe.

 

[disc1]

I think you seriously overestimate the amount of copper that can make it through a DI resin.

 

[GrahamJr]

I think you seriously overestimate the amount of copper that can make it through a DI resin.

And your comments are based upon what? Are you using a cation or anion resin in your DI filter cartridge? Do you know what others are using that may have potential copper issues? I don't!

I don't know if everyone is even using an RO/DI system or if they are how well it is maintained. There are alot of new reef keepers out there that don't even use RO/DI and can't figure out why they are havng poor luck rasing coral or why they have system crashes. This topic is to make people think!

 

[Yogre]

The tap water source is not the only source of copper contamination, although it may be the most significant.

Cu may be carried into the tank by fish food, salt mix, or supplements. Since we're talking buildup over time and deleterious effects can occur in the ppb range, I'm wondering if we shouldn't also consider some sort of copper removal from the tank itself.

I'm thinking about running Cuprisorb on my tank on an occasional basis... I won't be able to analyze Cu concentrations, but maybe I can see some subjective improvements. Couldn't hurt, at any rate.