Personally, I'll turn the water on for a few minutes, then shut it off and let it vent. Repeat until full. Takes longer, but I know I'm =full= when I leave. Getting one of those cheap meters off Amazon can't hurt, so you =know= how much water has gone in.
Lyle
2002 GMC Sierra 2500 HD Duramax Crew Cab 4x4
Banks Bullet Tuner and Monster Exhaust
B&W Turnover Ball with 5th Wheel Companion
2004 Komfort 25FSG Fifth Wheel
1936 John Deere Model A
International Flying Farmers 55 Year Member
My procedure is the same as Lyle's. I fill till it burps the first time. I then shut it off for a few minutes till it vents then resume. The only problem with that is time. When we camp at New York state Parks, we fill up on the way in to the campground. If I am holding up traffic, it drives me nuts to fiddle with the tank.
2011 Chevy 3500 HD LTZ Duramax/Allison Crew Cab Long Box DRW
B&W Turnover Ball with Companion