copper used in future fuge

[gkw]

Hi, I am new to here and to the hobby. And let me start off by saying what a great community you guys have here. Lots of helpful info and nice people. Glads I found it before I do anything stupid.

OK. I have a 125g tank that i just empty out (it was a cichlids tank before). I know some basic concepts on how to start it up already, but I have one question I am not too sure...well, one at the moment.

I am going to get a used 55g tank from a friend. It's gonna to be my sump/fuge... but I remember he had used some type of medication for his fresh water fish before. I don't want to take the chance of killing any invert in my tank. So, can I put aquarium silicon over the current one in that tank to prevent possible copper-leaks into my water??

Thanks!
GKW

[Michaelr5]

Is the existing silicone discolored? Is it blue or green?

If it is not discolored at all (clear or milky white) you are most likely safe.

If it is light blue the most likely cause is methelyene blue which again should not cause any problems.

If it is green, could me malachite green or a copper based. The copper could leach out into the water, but how much and over what amount of time, I could not say. I don't know if overcoating it with another layer of silicone will work. The best bet would be to carefully remove the existing, take care to not break the seams between the glass, and put new in. JMHO

Mike

[RAVEN]

If you are planning on doing a fish only with live rock (FOWLR) tank then you would probably be ok. You can always use a fine mesh bag and Cuprisorb by seachem. Its a copper absorbing resin that actually works from my experience. It turns dark purple when it is used up. This can be used to absorb any copper that would slowly leach out.