Brass fittings

We have a small pond with 2 reasonable sized goldfish which has been established for some time. The pond itself is fibreglass I think with a waterfall feature using two fibreglass trays.

I would like to add to the waterfall feature by using a large brass or more probably bronze tap, which is about 5 times larger than a common garden water tap. By directing the pump water through the tap and cracking it open will give the appearance of a tap dripping water into the existing trays.

My question is...will anything from the brass/bronze (eg copper, zinc or tin) affect the fish?

Thanks for any help,
Rod