Is it normal for the ¼ in of water I leave in the bottom of the toilet to leak out in a few minutes? Is there a solution to keeping the water in the bowl so the gasses from the black take stay in the black tank? We have only had four trips in the 369rl and when I tried to put some anti freeze in the bowl it leaked out in a few minutes. I tried cleaning the rim of the bowl ball and that did not appear to have made any significant difference.