copper used in tank: is it appropriate for a reef set up

[rebar]

There's a 90 gallon tank set up for sale on MR that many of you may have seen (there was a thread on this). Copper was used in the past so the rocks are not good for a reef set up. that was clearly the consensus on the thread. but i was thinking of purchasng the tank/sump for a reef set up. Would the copper actually have penetrated the tank? Doesn't seem likely to me, but i would other's opinion. thanks in advance.

 

[deelucky]

no

 

[marrone]

Once copper has been placed in the tank you can't use it for a reef tank. The silicone will have absorbed some of the copper, which just like the rocks, could release it back into the tank.

That's always the chance you take when you buy a used tank that at sometime point copper may have been used it in. You really need to be sure before you make the purchase.

 

[Craig]

can the silicone be removed and then new silicone applied? Silicone tubes are cheap and so it seems like a good way to revive a tank.

would this make it reefsafe again?

 

[tosiek]

To redo the silicone work you ideally would have to cut off the top and bottom moulding, then cut apart the 5 panes of glass. Then Scrape and remove all silicone that was on it, make sure no oils or anything are on the clean edges from anything you were using to remove the silicone 100%. Then resilicone the tank back together and pray you do it right the first time. Cutting out the silicone out of the corners and reapplying loses the strength that the silicone has on the corners and you might not get a good adhesion between the old silicone and the new that might cause leaks and/or strength issues.

Silicone is cheap but the work involved in siliconing a tank isn't. IMO i would wait for another setup like this to be for sale that hasn't had copper into it, but thats just me.

 

[Manny]

I kind of see where craig was going.
couldn't you just razorblade the silicone not between the glass and resilicone it neatly without taking the tank apart? Kind of like regrouting your bathroom:scratch:.

 

[Psycho graphic]

I myself think the idea of never being able to use a tank that has had copper in it for a reef is a myth. The copper absorbed is not a renewable source, it simply has to deplete at some point. If the fact that it cannot support coral life is true, tell the 50 or so Zoa frags/colonies, about 45 mushrooms, 4 leathers and other various corals in my tank that are allive and thriving, they should be dead by now. My tank was dosed with copper about a year ago, and about 3 months before being converted to a reef.

I'm not by any means telling you it is indeed safe, but I have had reef setups in tanks that have had copper in them more than once.

 

[tosiek]

I kind of see where craig was going.
couldn't you just razorblade the silicone not between the glass and resilicone it neatly without taking the tank apart? Kind of like regrouting your bathroom:scratch:.

That silicone bead holds alot of the pressure from the glass, unlike grout for tiles which just seals the spacing between and may slightly hold the tile there in case it gets loose. Could hold well if you regrout the silicone and you get a good adhesion between the two silicones and the glass but i wouldn't do it. =0)

 

[rebar]

The copper absorbed is not a renewable source, it simply has to deplete at some point.


This was my thinking on it...although not so clearly articulated in my own head...after time with copper-free water running throught the system, wouldn't any copper in the silicone move to the water through osmosis (or something like that) and with continual water changes ultimately be silicone free. especially if the tank has been running for a while?

 

[ellebelle]

Rebar, logically speaking, I think this is true. However, if you were going to test that hypothesis, you'd need to buy an extremely sensitive test kit - I would guess that you'd need to buy one of the proper lab test kits, the next "tier" of kits past Salifert. You would need to test your levels extremely frequently, and watch the levels of copper go down. And even then, if there are trace amounts of copper left in your system that you aren't detecting, it could result in the deaths of some of the more sensitive types of fish (like dragonets), inverts, and more sensitive corals (I noticed that a lot of the corals that psycho mentioned are fairly hardy corals). I guess I would say that if the price is too good to pass up (free, or close to free), there is no harm in trying by putting water in the tank and watching the levels go down to zero. But if it's more than that, why not wait for a copper-free system to come up? People are selling whole and parts of packages on here all of the time.

 

[rebar]

that's good advice elle belle. thanks, and thanks to the others as well.

 

[Psycho graphic]

My tank has housed 2 SPS for a while with no problems, I only took them out to put them in a tank with MH lighting. I also housed a Green Manderin along with plenty of snails and hermits, this tank was at one time overgrown with pods until I had a crash over late summer last year. The crash was NOT related to copper, unless any trace amounts can cause the ph to drop drastically overnight. So I have kept animals that are copper sensitive in this tank.

I have brought this point up of the renewable source more than once on a few forums, I have gotten many replies such as the one above, but not once has someone given a reply that makes any sense to me of how a trace amount of copper (that would be stored in the silicone) can forever leach back into the water at any amount that would hurt the inhabitants in the tank.

I should have pointed out, I used polyfilters to remove the copper in this tank after treating it, until my readings showed no sign of copper in the tank and then replaced with new pads for a month afterwards.