I spent today designing and crafting the framework for my LR. I made it out of 1" PVC from Home Depot. The spiral is a piece of flexible PVC. I have planned for a cave underneath the larger "shelf" that is on the right hand side of thee tank. Here's some photos of what I came up with. Let me know what you think!
this is a shot looking thru the cave:
opposite end of tank:
i know it's a lot of pictures just for LR framework, but I had trouble finding pictures on internet so I figured this may help someone else with ideas.