Thanks Curt. The grid in the back is to provide extra flow around the LR, and more stability to the rocks. I also have another sheet of acrylic behind the back grid. I will be using marine epoxy (if needed) to secure rocks to the back. I did not want to get marine epoxy on my tank so I used the extra sheet of acrylic on the back. Everything is held in place with Great Stuff. It comes off of acrylic fairly easily when cured.
Since my tank has a small footprint (18" in the middle and only 12" on the sides) I am going to try to do a step of of rocks from the front bottom of the tank to the rear top of the tank. I just hope it works. I'm new to this so we will see how it turns out. I should have water and LR in there in a week or so. I will post more pics then.
I guess I could just use zip ties to help secure the rock in back also. That may works better if needed. I used zip ties to secure the small fragments of coral on the sides of the eggcrate.
Mark