Well...Copper is good for treating fish, yes, however, i would not use copper and try to be pro-active...if it aint broke, dont fix it train of thought....
With new fish members, i recomend a FW dip or meth blue dip and then a 4 week quarantine period...I dont see a need to treat a fish for something if it does not have anything wrong with it....
Your levels of copper are fine...