I have a 84 Hunter 25.5 and have a couple of questions I would like help with. I have been putting off the task of cleaning out the fresh water tank since I've owned the boat . There was not an owners manual with boat so I am at a loss to know what size the tank is. I have read where one owner stated his was a 25 gal tank and then another owner stated his was a 12 gal tank, both the same year and same model as my boat. Was there such a big difference in the sizes of the tanks on this boat model ? Secondly, I mainly daysail with a few overnighters so I don't really need the fresh water, I use bottled water. So would it be better to leave the tank empty after I clean it or fill it to balance the boat or whatever reason? I know there is some water in the tank but don't know how much. I really don't want to refill the tank unless it would help the sailing ability cause I can use all the help I can muster up to be a better sailor! 