Here's what I did on my
Fiber Stream. I replaced the original bumper with custom brakets that fit within the tube frame, and then attached two sections of 4" PVC pipe. The bottom one is PVC weeping tile with 3/4" holes in the bottom every foot (for draining), while the top is solid PVC. Have a screw in plug on one end, and a blank cover on the other. Screw in plugs are on opposite sides. Slinky goes in the bottom, tarp poles in the top one.