I have a presto canner. The instructions say add 3 pts water to the canner, add jars, put on lid and vent for 10 minutes. Then put on the rocking thingie. Pressure can at 11psi for 75 or 90 minutes depending on jar size. I have trouble keeping the psi at 11. It goes to 15psi. I have read that this is okay, but mu concerns running our of water in the canner at this high psi. I made Ham and Bean soup yesterday using quarts and when cooled down, I opened the canner and there was hardly any water left from the 3 pts. Does the high psi cause the water to be used up faster? Should I add more water? Any help would be appreciated.