Hello, I'm fixing to dump my tank and start over and I'm wanted to use a new substrate. This tank will not have live plants just silk and real wood. I'm wanted a dark color like black or dark brown. I don't want big gravel and I don't want fine sand. I'm wanting something in the middle. I have been looking and can't seem to find what I want. Anyone have any suggestions? Thanks for any help...Oh I'm planning on making it a betta and maybe some ghost or amano shrimp tank.