Fresh water to toilet bowl
If you want to do that you should remember that on a live ship the fresh
water system is constantly pressurised and therefore fresh water will be
continuously seeping into your toilet bowl and draining your fresh water
tank. To avoid that you need a solenoid valve switched on by the red toilet
flush button to open the fresh water line when you do flush and keep it
closed otherwise. Also you should be careful about the possibility of your
toilet bowl water backing into your fresh water tank with all attendant
To avoid such problems you would have to run a fresh water pipe direct from
the tank to the toilet flush sea water hull intake (before the flush sea
water pump) and Tee it there. This involves more pipe runs in awkward places
but would be the safest way of doing it, both avoiding the constant pressure
problem and the potential water flow back from the bowl.
I had discussed this issue with Amel for my boat when ordering her but they
did not want to do it then. They'll come to it some day.
SM 212 "Satchimi"