I am pretty sure the copper would be on the label of "bug out" and the chlorine pucks, Other than that I don't know how to find out where the copper is coming from. I don't know where the metals come from in my pool- my water always test no metals, but I get stains, so I can't help you there. Maybe someone else knows more on finding the cause of it? But I do know that they can be controlled by keeping a sequestering agent in the water, adding the fill water through the filter, and keeping the ph on the low side. Post your chemical numbers (fc, cc, tc, alk, ph, cal,cya) and maybe I can see if anything is off.