Yes i think this would be very bad idea for sure while heavy metals like copper work well they are very potent and likely bad for the ray not to mention tuff to get out of the tank....I am 99.9% sure that any copper is not ray safe. What are you trying to treat? There is a list of ray safe medications and their uses in the sticky section. Using any medication with rays can be risky I would make sure it is needed before proceeding.