I think that if the plastic frames are original to the tank they should be identical in all measurements.
I think what the OP is asking is what is the width of the plastic trim underneath the tank where it contacts the existing stand.
Exactly. Here is a sketch of what I'm talking about. This would be the cross section of the bottom corner of the tank.
Originally Posted by Blue Ridge Reef
And for what it's worth, mine are built into a wall. I ran a plywood support board to lie on top of the Sheetrock edge to get it flush. I badly wish I'd have put a hinged opening above the tanks to give myself front access to them. Doing all maintenance from behind the aquarium has its challenges.
I really thought about that, but this is going to be right in the center of the entryway to the house. I really needed to keep clean lines as much as possible to go with the rest of the home design.
The way I look at it, is most of us can't get to the back of the tank for maintenance, so what's the difference? If anything it's a little easier because all of your plumbing, wiring, CO2, etc is right in the open vs being hidden behind the tank where you can't get to it.