Hi all! I got this idea from another member, bruiser. Thanks bruiser! I used 4-12" slate tiles and some GE Silicone1. Total cost-about $10. The final piece has a footprint of 11.25" x 8" and it is about 8" tall. The depth of the tank is 12" so it will fit very snug like I want. I kept the factory edge on the back and the left side so it will fit tight against the corner of the tank. I also used a hammer to break off the sharp edges to help protect the fishies. I have waited the required 12hours to let the silicone cure. But, to be safe, I'll wait until tomorrow to put it in the tank. (provided I don't smell the vinigar smell from the silicone). Here are a few pics. I tried to take pics that show the dimentions of the piece.