Used Sump Tank

I have a 40 gallon tank that I would like to use as my sump for a 75 gallon tank that I wish to eventually have corals in. The 40 was used as a hospital/acclimation tank and had copper put in it, I was told that the copper gets in the silicone and can harm coral is this true? Can I clean it with anything so I can use it or is pretty much unusable for my sump?

 

How old is it?? As long as it is cleaned out well I don't see it being an issue, but others with more experience can chime in..

 

It should be fine,Maybe fill it up and then test the water for copper before you hook it up to your main system my friend just did pretty much the same thing as you and it worked out for him.

 

+1, except I would let the tank sit for a few days with water in it before testing.

 

Copper cannot get into the silicone, if it could then we would all have water on the floor and not in our tanks because that would mean that silicone isn't water proof.

What it can do is get up under any loose edge of the silicone. All you really need to do is clean the tank really well, maybe hose it off really good hitting the corners with a really good hard stream of water.

Once that is done you should be OK to go.

 

Just because something is water proof doesn't mean it can't absorb other substances or elements (i.e if I paint something, it absorbs or adheres to the surface but doesn't bleed through)
I've heard a lot about copper leaching into silicone on both sides of the subject, I'd do the water test just to be sure.