Greenhouse Bellow Testing

This is the Alpha build. It’s a double poly film lean to post framed passive solar greenhouse. I’m testing a bellow I made for $1 or less. It’s designed to hold the air in after it’s inflated. My goal was to inflate it just once. I’m at 13 minutes to fill it, then it holds for 1.5 hours, and only took 7 minutes to top it off. I know a differential switch would work, but I’m broke in my moms basement. I am extremely blessed and wanted to share what I’ve come up with for all you Greenhouse lovers.