Believe it or not, but there are many additives aimed directly at reef aquariums that have copper in them. That’s right, the nasty “C” word has surfaced once again. Most of these supplements are the bottled trace elements products, but there are several others additives that have copper as well. And in most situations, the element is listed right on the bottle, sometimes with the concentration included. All that said, there’s no need to be alarmed if you run to your tank and find out a product you’ve been dosing has copper listed on the label. Copper is a natural substance that is found in the waters surrounding every wild reef, and it does have some usefulness in our reef tanks. I’m not suggesting that you run out a buy a bottle of copper to start dosing to your tank, but do be aware that many products offered today have some form of the potentially harmful chemical in them. These products have been known to cause some troubles, but for the most part aquarium hobbyists haven’t noticed many issues.