Here is one--with butt joints.
The reason you don't see many plywood stands (with no lumber,) is the typical DIY'er knows very little about structures, and decides that overkill is the only way to feel comfortable enough to sleep at night, understandable, but does not alter the point that any standard sized aquarium ( to prevent the one person from asking about a giant custom tank) can be supported by nothing more than a structurally sound plywood box--with no lumber--save for special concerns. (Long open spans in the plywood--and perhaps not even then) Not even the 1 x 4 inside would be necessary.
Someone mentioned 4 x 4's. The point to be made here is that 4 x 4's are about the most dimensionally
unsound of all dimensioned lumber. For whatever reasons, they warp, twist, and crack to a far greater extent than any other dimensioned lumber. If such strength is
really needed, you will get better stability out of "laminated" or doubled 2 x 4's.
I haven't really ever addressed the desparity between RocketEngineers stand design, and that which is
really required. It is a great thread, a solid design, geared toward the typical DIY'er, that does not have a background in sturctural design, material strength, and the knowledge to put it all together properly: engineered strength. But even with all that lumber, if it is not put together right, it will all hit the floor.
What is unfortunate though, is that if you build a stand indentical to many manufactured stands--required for use if wanting the warranty of the tank honored--there would be no shortage of well meaning folks, that will say: "That just is not safe."
In the end it is all about "sleeping at night." There are not
any stands that I have ever seen, plywood, lumber, or steel, that an F5 tornado, will not toss down the block around the corner, and up in a tree--right next to your car. A couple thousand pounds is just not really a significant load.
A word about the humidity: Not really a problem, after a couple coats of primer, and a couple coats of paint. To keep mildew out of the picture, you may wish to cut some openings in the back panel for ventilation.
http://reefcentral.com/forums/showthread.php?t=1213499&page=19
Looks good, how's it working out these days?
