Quote Originally Posted by hclchicken View Post
What's the downside of using a mesh wire inside your overflow to prevent critters from getting in?
It's probably not a good idea to use any metals in your tank that aren't recommended for aquarium use. They will leach trace metals into your system which is never a good thing. I've seen lots of people cover their overflows using nothing more than egg crate/light diffuser. It's a plastic material and won't harm your system.