Copper treatments
 

Is there any safe way to get rid of possible residue left over from treatments in a tank? I have a real nice 120g FW I would like to convert to reef at some point, but I know it has been treated. Does the seachem stuff work (cuprisorb or whatever it's called)?

Cuprisorb does a great job at removing Cu from the water column. The concern with a previously treated tank is that some copper may have gotten into the silicone where it may slowly leach over time. I've never seen any proof of this, but that's the thinking.

Perhaps you could ask Seachem what they think as the company is usually very good at responding to queries about their products.

I thought I read somewhere that muriatic acid might do it. Fill the tank with water and add acid, then after soaking for a few hours, drain it somewhere you can neutralize it with baking soda (into the bathtub or something) and then refill with water and add some copper removing compounds. Let sit for a few days, or longer.
Try and double check my theory, I'm only half certain this was what i read.