poking holes in the 'copper' tank theroy.

[khaosinc]

Ever since I got in to this hobby (ok addiction) I've always heard that once a tank has had copper in it, you can never use it for corals/inverts. Always been a bit sceptical.. but wasn't planning on pushing it.

I just did a test somewhat unintentionally over the last few weeks and now I really don't buy it.

When my tank split a seam at the end of March, I grabbed every tank I had, plus buckets and my mixing trash can. What I didn't realize until I took everything down last weekend to get in the new sump, was that the 55 that I put ALL of my corals, shrimp and alot of my snails was the tank my stepdad used in his science classroom for several years breading south American cichlids as a yearly class project. I know for a fact that it has been treated for ich every semester for about the last 10 years. All of my inverts, and all but 2 corals are fine (both died do to falling under some rock) are fine after being in there for the last 6 weeks.

Conclusive.... NO, but I wouldn't toss out a tank just because of that in the future...

Just my opinion,.

[walkthedog]

The first reef tank I set up was a 55 gallon that Had been freshwater. I had used copper in it and converted it to a reef. I didn't have any problems keeping inverts /corals. The thing about copper is that it is lethal to inverts at a very small dose. If the tank is not cleaned very well then posioning by copper would be easy to do. I have heard that it gets in the silicone and leeches back into the water. If this is true, then my first tank would not have been successful. I'm not saying that you can't get copper posioning from using a tank that had copper in it. All I can say is I didn't. I agree with you. You don't have to toss the tank but I would test to make sure I got all the copper out.( If I had to do over again.)

[greenbean36191]

Also, keep in mind that copper toxicity is cumulative. A few months of success doesn't mean you've dodged a bullet. If there really is any copper leaching from tank sealants then it would be in very low levels that would take a long time to become apparent.

[billdogg]

IMO, the possibility of enough copper leeching from silicone to harm your inverts is, at best, slim. I have had no problems with my 60 cube, and i know for a fract it has been heavily coppered in the past (back before i knew about hospital tanks, etc). It still has the same huge chunk of sculptured lava in it that i put in it almost 20 years ago - it's been coppered too. it is now my reef tank, and is doing quite nicely as such for about 15v years. if anything was going to leech out and accululate, it surely would have by now.

when in doubt, use a little polyfilter to remove any residual copper and all will be well.

[ChknWing]

<a href=showthread.php?s=&postid=15009147#post15009147 target=_blank>Originally posted</a> by greenbean36191
Also, keep in mind that copper toxicity is cumulative. A few months of success doesn't mean you've dodged a bullet. If there really is any copper leaching from tank sealants then it would be in very low levels that would take a long time to become apparent.

So due to the slow leaching effect could we not deduce that with regular water changes you are probably removing the copper that gets leached into the system

[Hal]

Carbon also removes copper. For whatever reason this isn't well known, but it's true.

I had snails living in a former QT that had been repeatedly dosed with copper. My snails lived there for a year before I transfered them to a different tank. The only thing I ever ran in the tank was carbon. At one point I also had aiptasia living in the QT with no ill effects (food source for a QT'd copperband).

[patsfan1130]

I've not conducted any experiments to support my opinion and all I have is years of experience but I feel it's bunk. I've used countless "copper" tanks over the years and never experienced any problems. I always clean with water/vinegar regardless of what is in the tank prior first. After that, it's good to go

[Anemonebuff]

I've used them without problems as well.

[jenglish]

I think most tend to err on the side of caution. If the silicone sealant is stained with copper, it may be problematic. I think a acid wash will be good enough for most tanks. They make copper absorbing media (cuprasorb IIRC) or one can always fill it w/ FW and throw a feeder shrimp in as a canary ;)

[rendogg]

Daphnia are excellent "canaries in the coal mine". They can be used as copper testing fodder, if it's good enough for Daphnia it should be good for even the most sensitive inverts. They also make an excellent treat for your fish after your done!:)

They do, however, require good, clean, established water to survive.

[LobsterOfJustice]

I've reused copper treated tanks, rock, and sand with no problems.