Alright . . . . here is the scoop. First off, I must say, read it completely, then think about for a minute before you decide if its for you or not.
I took measurements of the foot print of my tank. 24" x 12" (22gallons)
I then went to Home Depot and got cinder blocks and a sheet of plywood. 6 cinders to be exact which conveniently when arranged in two layers of three bricks was nearly identical to the footprint of my tank. Then I put down a 24 x 12 piece of 1/2 inch foam insulation board down on the blocks. I then placed a 24" square piece of 3/4" plywood on top of the cinders so that there was a 4 inch overhang in the back, and about six inches in the front. then I took a black linen tablecloth and draped it over the whole set up so that it touched the floor in the front and sides. Then I put a sheet of plexiglass over the top that was 24" square. Put the tank on top, level the stand with shims and you are good to go. The foam board absorbs some of the weight shifts so it will level itself up to about a quarter inch. The overhangs double as splash guards as well as a ledge on the top to carry out maintenance, and underneath it creates a small hidden storage space.
Once this is set up, it is VERY stable. Before I put my tank on it, I stood on it and rocked back and forth as much as I could to try and knock it over. I mean I really tried, and couldn't do it.
A couple things to keep in mind:
I only have a 22 gallon tank, and the stand sits low to the ground. It is only 2 cinder blocks tall. That and I dont have a sump of any kind. I dont know what to tell you if you do other than to be creative.
Now for larger tanks, i have seen this done as well and to be honest, I didnt know until I looked under the sheet. The largest tank that I have seen this on is a 55 gallon. It was done with four pillars of three cinders tall and two cinders wide. Each pillar was 2 bricks on the bottom, two more perpendicular to those for stability, then a sheet of plywood across all the pillars to make a shelf. Then two more cinder blocks on top of each pillar then the same set up that I used on mine. Its been like that for about two years and no problems. The only difficulty that he has is that when he spills water onto the sheet, it stains and looks kinda crappy. Hence the sheet of plexiglass I used. Easy to wipe clean.
Like I said, its not for everyone. But for those of us on a budget, it really cant be beat IMO.
Justin