Peggy, I purchased your book a few weeks ago with my spring project in mind. I noticed last year an odor coming from around the holding tank. Further inspection found the vent hose connection at the tank had been leaking dispite the PO's caulk job. I have a 1993 H33.5 with the origanal 20 gallon aluminum holding tank. Realizing I'm on borrowed time given the tanks material, this springs project is to replace all the sanitation hoses and holding tank. The Par toilet still works well though I've purchased a rebuild kit which is also on my list. Ronco has a tank that will work well dimensionally. I have two questions. First, Ronco's illistration of a typical holding tank installation on page 88 shows a pump discharge hose being near the bottom of the tank to allow for complete evacuation. With the way they show it won't waste sit in that hose and eventually permeate it? The second question, realates to the picture I've posted. My current system has a Guzzler hand pump in the discharge line for manual evacuation. Can it suffer from the same permeation problem my old hoses may have? Thanks for your book and future help.Jeff