I am looking to install a holding tank in the bow of my Tanzer 26 and connect it to the working Jabsco Head.I have a 12 x 14 x 17.5 tank picked out. It will hold 12 gal. How many uses of the head will fill up the tank? Is this a reasonable size tank for day sailing for 2-4 adults and several overnights for two of us. I am hoping that a tank will smell less than the porta-pottie.Does this make sense especially as Casco Bay,where I sail, is a no-discharge area.Does it seem like a good idea to put a hole for intake from the head in the end of the tank facing the stern, put two ventilation holes on the top and the hole for pumping out in the bow-facing end of the tank? Any ideas will help as you can guess I am a newbie in these efforts.Thanks Gerry