just remember if it looks like it barely holding on just half filled or totally filled with water, doesn't mean anything. testing my first homemade acrylic tank lulled me into that false sense of security. rocks and sand are more dense then water, hence if the stand looks like it can barely take a tank full of water, the rock and sand might be enough to kill it. it might be ok for the first week or two, but a few good vibrations and its commin' on down, and i don't mean to the price is right.
take it from me, if you think somethings not right, it probably is. where did you buy the stand? can you take it back and get something better?