I, too, suspect it would be extremely difficult to tip an 18" deep tank over backwards if the stand footprint is as deep as the tank. However, I was thinking further about what the absolute requirements of a stand actually are, if not a base with the exact same footprint as the tank's, and placed immediately beneath it at all points, and I've realized that what we all commonly think of as a "proper" aquarium stand may not be required for "proper" support. In thinking about my 125, with a 72" X 18" footprint, I realize that, as long as the material of the stand is strong enough, and the design and weight distribution is equally distributed across the footprint of the tank, then the legs and feet of the stand don't absolutely have to be at every corner or midway along the front and back, either. For instance, a tank the size of mine could be supported merely by one foot in the middle (front to back) of each end and one foot midway along the front and the back, with just four feet placed in a sideways diamond pattern. And actually, if you get right down to it, even the legs at each end could be moved in a foot from each end (just four feet apart) without being unstable, because from end to end, something would have to pick up one whole end of the filled aquarium a few feet high to get it to the sideways tipping point. Heck, as long as the material and bracing design were strong enough, you could probably safely bring them in to only three feet apart. However, I do think it's a given that the back and front legs should be the full 18" directly beneath the front and back of the tank. I used to have a stand for a 55 that appeared to only have four legs (one at each corner) that held the cabinet about 5" off the floor, and it looked very nice--very "furniture-like", but it actually had a fifth leg right in the middle, directly beneath a center divider inside that partitioned the two shelf areas and supported the center of the stand top; this same five feet configuration could be used on much larger tanks just as well. I'm working on some of these, what might be considered "radical" designs, for my new aquarium stand, and I have to admit that it is a little exciting getting away from the everyday "big box beneath the aquarium" design and looking at the bare essentials of what is actually required. I'm finding, of course, that the more radical the design, the more "utility space" is lost beneath the tank. It is interesting to look at it differently, though.
And as far as that "100 gallon" tank on the table goes, it might would work just fine IF the tank footprint was properly supported and the little legs were braced sufficiently, but if that thing ever even starts to lean sideways, it's ALL coming down fast and it ain't gonna be pretty! lol :eek5:
edit: (On second look at that 100 gallon on the "table", now I see that it looks more like it could be an older TV stand or some other box-shaped piece, which might would suffice for the weight, but then there's the unsupported ends hanging off.)
I used to live in Natchez when I was a kid and one summer during college (when I used to hang out with Greg Iles a little, playing music), and I still have some relatives in that area, but now I'm in Philadelphia, NW of Meridian. Do y'all get over this way and visit much?
Olskule