Oh yeah, about the rusts and all, its kinda true that these metals don't flake off, but to some extent, it still does ionize, and these bits still get oxidized and precipitate out. You'll notice its effects after a few months or years. Small problem, but I think most people would want to keep their comps running for a few more years. You can add a filter to overcome this problem, but I think its not worth the trouble. You'll have to get a bigger pump for that.