"This stand is was not produced with precision machining and manufacturing so it's difficult to get it assembled properly. The one I saw at a Petco store was skewed and wobbly simply because whoever assembled it did not have the time, strength, or implements (very large mallet and solid block of wood) to get it optimally "adjusted" during assembly. Nevertheless, I liked its functional and non-obtrusive appearance (much better than vinyl covered press board, IMHO) so I elected to give it a go.
The legs are very difficult to fully engage in the "shelf" receptacles--especially when using the foam tape "filler" suppled in the box. Whatever it takes, these legs MUST be fully engaged. I used a large mallet and gave it a very aggressive pounding behind a protective wood block (alternating leg sockets in rotation) before all eight leg pins were fully seated in their sockets. I thought I might break the welds at one point but they all held. I recommend wrapping heavy paper and/or masking tape around the legs to protect the paint from the mallet. It's tough not to occasionally brush the legs with the mallet and the paint is pretty soft. Once the legs are fully engaged, it's necessary to twist the shelves / legs in opposition so they link up squarely. (You need to make parallelograms into rectangles. ;)) A small to medium size person may need to find a way to gain mechanical leverage (jam it in a door frame with 2x4s or something). I weigh over 200 lbs and just jammed my legs and feet in it and reefed on it with my hands.
Now that the stand nice and straight, it holds my 10 gallon very securely on medium carpet or hardwood floors."