i installed a solar vent in addition to the 12v DC fan that comes with the head, the power draw from the DC fan is insignificant even with the fan running 24/7. It is the same type of fan used in a desktop PC. The solar vent alone will suffice resulting in a zero draw on the DC power system. The starboard tack factor is only really an issue on a long distance cruise but it would be foolish to deny a lady in need under any circumstances. Regular toitet toilet paper and coffee filters as a bowl liner are used. The easiest way to vent the composting head is to install a solar vent in place of the deck pumpout, no need for an additional hole in the deck. The composting head also allows you to cruise off season when most pump out stations are closed. Urine can be dumped overboard since it is 100% sterile with no impact on the environment.
