Fresh water flush?I pump out holding tank then shut off water intake and add pink anti freeze and flush until the pink flows back into bowl. This is with electric flush.
I'm not sure how it happens either but when the water supply is shut off and I go through the flush cycle the pink stuff flows back in from the rim of the bowl and then goes down the drain. Someone posted a video of how a head pump functions a few weeks ago. The video showed how there is a valve that is supposed to open and close. It sounds like many members has a similar function of disfunction with their heads.Fresh water flush?
I also don't fully understand how you get pink fluid flowing back into the bowl. Where does it come from (unless the system is fresh water flush and the fresh water has been treated with antifreeze.
Yup -Replace that almost every year as neededIf the fluid from the holding tank is flowing back into the bowl, it could be an indication that a joker valve if equipped needs replacing. That is a simple and inexpensive repair but can be messy. The jocker valve is a rubber 'duck bill' type of unit that allows flow in one direction but not the other. The valve allows the contents of the bowl to pass into the discharge hose and eventually the holding tank. When the flushing stops, the valve is supposed to close to stop back flow. Not all marine toilets have a joker valve but most have something similar that usually requires periodic replacement.