I have built several stands and I used to build them out of 2x4 and even 2x6. The stand was firm, strong, cheap and can hold a real tank. After wrapping it in cheap plywood, I could barely fit a 10g tank underneath. so much space was lost. Then I went to a pet store to look at their stands. 240g tank held up by flimsy 3/4" mdf. Some 100g tanks were made of 1/2" plywood.
That's when I realized I way over engineered my stands. If the stand is to be painted, they are made of 3/4" baltic birch plywood. Loose tenon joints glued together using titebond 2. Walls are supported using 4/4 stock of beech. However, if the customer wants to stain, I give them their choice of wood and match the wood through out.
