peggy, this winter i installed a new plumbing system & head after reading your book. raritan phII head, ronco tank, raw water intake, no y-valve. i installed the tank in the v-berth. both the 1.5" pump out line and 1.5" intake from the head are tapped into the top of the tank. the 1" vent also comes out the top of the tank with an elbow, runs about 5' horizontally to the bow then turns up about 10" and vents out a thru hull i installed in the side of the hull near the bow. first used the head about 3 weeks ago. it's only been used about 7-8 times over the last 3 weeks. mostly doing # 2. this weekend i was down and noticed when i lifted up the engine cover and some of the lazarette covers, it smelt. i then lifted up the v-berth cover and noticed it worse. i read your book again and in the interum, poured some white vingar & clean water down the head. since the vent turns up vertically, do you think i have to install another vent to get some cross ventilation. the second vent would end up running the same way as the first but would come out the starboard side since the first is on the port. would a second vent installed with the 10" of vertical on the end still create cross ventilation? one other thing. when flushing the head, will there always be a little water left in the bottom of the bowl. no matter how much i pump, there is always a little water left.