This is the EZ Rect boltless Type 1 shelving that is 8 feet long, 30 inches wide and 38 inches tall. I've cut this shelf down to 38 inches high for putting a tank on and to view the tank at about chest level.
http://ezrect.ca/type1.htm
I have the XHD Tube Frame Connectors with WT Combination Tie Bar & Shelf Support and its rated at 1700 lbs evenly distributed for each shelf.
Here's a pic of the overall system:
Here's a pic of how its attached to the posts:
Heres a pic of the cross bars and XHD tube frame
