Catamaran aqua cruiser
I have a 1995 catamaran aqua cruiser 14x48. It has 80 gallon black water holding tank that is located in one of the fiberglass pontoon. I have owned this boat for 9 years and recently started having a horrible smell in my black water tank. I have been using the same chemical treatment. I’ve been trying to check on possible causes and read that there may be something in the vent. Can anyone please tell me where this vent might be located? We have looked everywhere and can’t find. The only opening is the pump out hole on the side. Any suggestions would be greatly appreciated.