Nah, they were vents that went into the room behind (soon to be fish utility room). They weren't connected to any ducting, so I took the grates off. I'll cover them with drywall when I get to the finishing stages of this build. The top one will be in the way when I put in the access doors. I don't have to put them in, but for the sake of photography, I need to be able to place remote flashes within line of sight and above the tank for overhead flash.

