Starting G out of water

[GMLIII]

GMLIII Seems to me like you can do that without any issue but I have found that without any pressure, once you drain the water out of the system...the impeller does not always like to suck in the AF since system is no longer primed with water so it sucks air (flush pro has a fitting that compresses the ball so not a ton of room for the AF to bypass without pressure, you may not have that issue on your hose attachment tho.. I actually made a 5 gallon bucket last Spring with hose end on it for this purpose. If there is water in system and its already primed, it will pull it thru no issue but once you drain all the water (at least for me), it was an issue and would not suck in the AF thru the flush pro.
What I did is buy a cheaper sump pump from harbor freight. I put one end in my bucket of AF and screw the other end to the Flush Pro....I start up the sump pump and then immediately fire up the engine. Since the pump is "pushing" the AF thru, obviously no issue priming and in about 45 seconds, I run 5 gallons of the AF thru my system and fill it (start coming out exhaust at 3.5-4 gallons). I also usually remove the thermostat and pour some AF down that hose since unless thermostat is open, I assume none gets in there. Only needs about half gallon and it starts running out exhaust, but figure its good peace of mind. Don't know if that part is needed or not.
I like the AF for the double protection against freezing....supposed to have anti-corrosive qualities so no corrosion can build up in engine due to left over bits of water...and assume that keeping the impeller wet will also keep it in better shape, tho I always replace that in the Spring anyway so it does not sit over winter and possible take a set.
This is of course using the RV anti-freeze that is non-toxic

Makes sense