I noticed in the first and second picture that you did not install the additional 2x4 along the inside joint of the legs/top/bottom frame (green pieces in post #3). These are in place I believe to help prevent racking and are very important.
Others can chime in as to whether or not this matters since you skinned the stand. I wouldn't have built it without them personally.
Thank for your concern I try that too... but I has make the internal overflow system so the tank maker said will block the piping system.
