When is a good time to replace your anodes?<br /><br />I don't think mine need them yet, but I was wondering when the rest of you do.<br />My book says 'when they are about half worn' ... problem is.. what do they mean by half?<br /><br />I can't find a 'dummies guide to replacing anodes' Anyone have some pictures of going bad/very bad anodes?<br /><br />And lastly, should I stick with the zinc anodes or go with aluminum?<br /><br />Thanks,<br /><br />H.