Thanks for the input. Actually, my overflow hose is configured in a loop, which forms a water trap (like a "P" trap under a sink). I just presumed that is the way FR intended the overflow hose to run. When there's water in the overflow hose trap, air doesn't escape from the freshwater tank.
I have presumed that FR intended the overflow hose to hold a small amount of water so that varments couldn't crawl up the hose and into the tank.
I'm thinking that the best solution might be to shorten the overflow hose, thereby eliminating the loop that holds overflow water in the trap. I figure that if I shorten the overflow hose and eliminate the loop, it will be a straight run from the tank to the overflow hose outlet and no water will be trapped and air will easily escape from the tank upon filling.
2002 Windsong - 34'