This video is a few years old so you probably figured it out. Never do exchange on propane tanks, you get a lot more for the same price getting them filled. I also always turn my gas valve on the tank off after every use, I have had the grill leak gas on many grills. Your zucchini looks amazing
If you went through a tank of propane in a month you have the valve turned on too high, it only needs to be turned on a little, I BBQ a couple itmes a week and I use a tank every three months.