Its definately a fun toy. Jan is usning it to kill majano's this week.
I think that using different metals would be fine, but I can't think of any readily available small guage wiring for dirt cheap.
For me, the copper isnt a worry at all. I only burn off 1/4" off wire on one side (typically it loses its strength because its thin and not totally disolved and I cut it off) after about six uses, or 20 aptasia. I only use it every other month to kill four or five of them and do a 20% WC monthly. OK so lets say 10% to be realistic. So, 10% WC's over a years time is 120% clean water for my total volume for a quarter of an inch of wire that became thin. To me its negligable.
For someone with a 40 breeder going on a rampage and killing 40 aptasia, I'd be just as worried about the massive spike in nutrients from killing so many pests than I would the copper. I'd recommend a big WC anyway.
