All that being said, you may want to first change your water feed to the head to fresh water, even for a test period to confirm the source cause of the pong.
Connecting a sea water toilet to the fresh water plumbing is a bad idea because it risks contaminating the fresh water supply with sea water and also bacteria from the bowl...and every toilet mfr specifically warns against in in their installation instructions. Determining the source of the odor--tank or toilet intake--is a simple matter: Odor in the tank results in odor out the tank vent too. Replacing a worn joker valve should keep it out of the bowl. Odor from dead and decaying sea life or even just sea water left to sit and stagnate in the intake line and pump shows up the bowl when the toilet is flushed...and usually is present in only the first flush after the boat has sat for a few days unless animal or vegetable sea life has been pulled in to die and decay in the intake plumbing. The most common sources of an all pervasive odor inside the boat are permeated sanitation hoses and/or a wet dirty bilge in serious need of a thorough cleaning.
--Peggie
Connecting a sea water toilet to the fresh water plumbing is a bad idea because it risks contaminating the fresh water supply with sea water and also bacteria from the bowl...and every toilet mfr specifically warns against in in their installation instructions. Determining the source of the odor--tank or toilet intake--is a simple matter: Odor in the tank results in odor out the tank vent too. Replacing a worn joker valve should keep it out of the bowl. Odor from dead and decaying sea life or even just sea water left to sit and stagnate in the intake line and pump shows up the bowl when the toilet is flushed...and usually is present in only the first flush after the boat has sat for a few days unless animal or vegetable sea life has been pulled in to die and decay in the intake plumbing. The most common sources of an all pervasive odor inside the boat are permeated sanitation hoses and/or a wet dirty bilge in serious need of a thorough cleaning.
--Peggie
