So... i have a large custom tank made 15 years ago.. each side overflow the total width of each side of the tank.. I will post a pic.. the overflow is two squares (rows) of egg crate that sites on top of the side of the tank.. its cracked and time to replace.. thinking I could do some type of 3d printed overflow... maybe do a few of them so i could remove, clean and replace as they get encrusted with Coraline algae ..