I don't know how your storage tube on a 19 was originally installed, but I completely replaced the original on my 17B, and added straps.
The original tube was sewer line type PVC, bolted to a frame plate from the inside of the tube. This was a big improvement over previous installations I had seen, but the sewer hose end had to have two tabs removed to fit into the PVC tube, and the sewer hose lacked a fitting for the other end. I wanted different sewer hose, so bought the Rhino-Flex brand and a new Valterra storage tube, made for RVs. I bolted on the new tube through the inside as before, but since the Valterra tube is a little flimsier than PVC, I added 6" stainless steel hose clamps around the plate that holds the bolt. It's between the bolt and frame, and is very secure.
Sorry I don't have a photo immediately available, I didn't think to take one.
2009 Tacoma Crew Cab, TRD 4WD
2007 Tundra Double Cab TRD 4WD
2014 Escape 19
2007 Norwegian Elkhound "Baxter"