Copper in trace elements???

[patm]

My tank has been doing really well with minimal additives such as calcium, but I figured I'd try something new to see if improved things even more. I wanted to add trace elements, so I ordered Seachem's Reef Trace. When looking at the back of the bottle for the ingredients, I noticed Cu (copper) 0.0032%. This seemed kind of wierd that copper would be in a solution to benefit corals. Is such a small amount actually good for corals? or is this a bad product? I haven't used any yet, so hopefully someone can help me out.
Thanks in advance,

Pat

[Leonard]

Copper, in small quantities, is essential for metabolic processes in marine life (all life, to be exact). Cu serves as a componet of key enzymes. It is when copper reaches excessive levels that it is toxic to life (Copper is the third most toxic metal, behind mecury <gasp!> and silver). Invertebrates are especially sensitity to copper poisoning. Lethal concentrations vary from organism to organism, but I would consider any levels above .5ppm universally unsafe. Obviously, the trace element contains far less then this, especially once diluted. Note that many additives include some copper: B-Ionic, for example.