I am not sure why they do not offer the 3/4" hose in black (typically this is made with rubber when is less permeable to odors). My current vent line travels about 3-4 feet horizontally out of the top of the tank before it begins to go up to the station base - I think that may be part of my problem. When replacing the hose I intend to ensure there are no sags and try to get some vertical lift to it to avoid any possible accumulation in the line. The vent hose is connected to the stanchion under the deck and then the stanchion has a hole about 6 inches above the deck. I have never had any issues with the stanchion sealing, but will revisit that again just to make sure. The vent hose itself is never exposed to sunlight in the 9 feet that it travels. I think the current vent hose is just that cheap solid white plastic hose intended for water (not waste and not odor proof).