Plywood stand for 60 cube question

[trmiv]

In the process of building a stand for my 60 gallon cube (24x24x24). The stand is almost done, and I've decided to build a second box next to the stand that will have a top-off container, all electronics and a refugium. To get the cords, pvc, tubes, etc to the sump under the main stand I'll need to cut a hole in the side of my stand. I just want to make sure it will be structurally sound after I do this? The stand is made out of 3/4" oak plywood. The sides are solid pieces 31.5"x26", the front is 31.5"x 22" but has a 23.5"x15.75" hole cut in it for the door. The bottom is also a solid piece of 3/4" plywood. The back is not a solid piece of plywood, but has 22"x6" pieces of 3/4" at the top at bottom to join the back to the sides (well the bottom piece is there, top piece still needs to be cut and installed. There is also a set of 2x4" supports to support the back of the tank, since the stand is bigger than the tank (the front and sides of the tank rest exactly on the vertical edges of the plywood). The entire thing is fastened with pocket holes and glue.

So if I cut another large hole, say 15"x15" in the left side of the stand, will this entire thing stay structurally sound enough for my tank?

Here is the front and back of the stand in its semi-trimmed state. Lots of work still to be done! BTW, this is my first time building a stand or doing any kind of wood work, so go easy on me.

[IMG]http://i54.*******.com/2dklo2u.jpg[/IMG]

[IMG]http://i56.*******.com/33kst9u.jpg[/IMG]