Used a copper algaecide about 3 weeks ago, my copper level is .5 according to a pool store computer. Kid behind the counter said that since I'd used an algaecide, it was likely introduced from that, and I don't need to do anything about it. (He didn't try to sell me anything, wow!)

I thnk he's correct, but I thought I'd ask - will this level affect anything? Do I need to do anything about it?