If you’re setting up a new tank or redoing an existing one and you’ve decided to use egg crate under your substrate, here’s a tip to save you some hassle down the road; for medium to large tanks, don’t use a single piece. Consider cutting your crate into sections, depending on the length of the tank. Why? If you decide to change your substrate, but you want to see how it will look before you do the whole tank OR you want to change the substrate in only part of the tank, having a single piece of egg crate will require you to remove everything from the tank. If you cut your crate into two sections or more, you only need to take out the section(s) that you want to redo.