Chew, I think most of your questions about the Fresh Head will be answered in the owners manual for it Raritan Fresh Head owner's manual As for backflow...Unless it's caused by back pressure, 90% can be prevented no matter what make/model the toilet is by switching to dry bowl to pump bowl contents to the tank. A second flush of a little clean water will ensure that any backflow is just clean water.
--Peggie
--Peggie