I have not tried copper but there are still a few guys pulling copper for lakers so someone should know. I switched all my diver rods over to 20lb fireline, because I hate wire, and seem to get less fleas. Last week my rigger rods with mono down 80 feet were loaded with fleas and my divers had only a few out 200 feet. I put 560 feet of 30lb mono and then 375 feet (125 yards ) of fireline. On Cayuga I have never had to get to the mono. I think it may be too thin and slippery for the fleas to hang on to but am not sure. Sent from my SM-T580 using Lake Ontario United mobile app