I'm building a large tank, and I don't know how to make the window properly.The tank walls will be cement The window is a sheet of acrylic 48 x 96 x 1 inch thick.Do I make the walls, then attach the acrylic to the opening, or do I set the acrylic into the wet cement. I can't find any info on this. Does anybody have mr.4000's website.every time i click on a link for him it isn't availible or it directs me to something else.. I know he has experience on this stuff. Please help me ! Suggestions please....