single layer of plywood, birch 3/4" about $50 a sheet, 4 sheets total, 1 4'X8' piece as the bottom the other 3 had Lowes cut to my diseired height of 32". Then had 1 basically cut in half for my sides, 46.5" to be exact so I wound up with 1 full sheet 4'X8' as my bottom, 8' long 32" tall for my front and back then 2 sides of 46.5"X32". The front and back are 3/4" thick so thats 1.5" total, 1.5"+46.5"=48" aka 4' the width of the bottom. Use lots of wood glue, the strongest I used titebond 3 and screwed the plywood together about every inch, lots and lots of screws. Go to harbor freight and buy 60" aluminum wood clamps they are like $12, get atleast 4 and 4 more longer then your total height. You can use 6" clamps on the front after your window is cut out. Get a full size L square. I first glued the back panel on top the bottom and used a clamp every foot, wish I had more but I moved them after I screwed near the clamp, using the L square to keep it square, then did a side at time allowing clamping time. Since I did 2X4 brace I left 3.5" around the edge of my front piece and cut the rest out for my viewing panel, its gives you more then enough space to mount the glass and when you add the bracing its even. Make the front and rear bottom and top braces 8' 3", leaves you 1.5" on each side and covers your plywood joints, the sides will fit in between then add your vertical braves. The 60" clamps are needed to clamp the horizontal braces as they will be 51" after the tank which is 48" and front and back 2X4 which are each 1.5"
