Russell, it was your comments some time ago about filling the tank to the brim is why I do that also. You are right, I have less problems filling to the top, but how do you keep all the water inside the tank? I think you also use the Pearl's transport tank correct? When I fill right up to the very top, I get water coming out of the zipper area when in motion so I keep it about 1" from the top right now to help keep that water escape to a minimum.