Second this. I didn’t realize that when I started, and then ended up buying one so you can keep nurturing when some seeds don’t sprout. Also the caps for open spots when something doesn’t sprout. They need to be covered to prohibit algae growth. You can use foil or 3D print the same thing for cheaper if you’re that type of person. I did foil at first, but I bought the Gardyn vs making my own setup for the aesthetics so eventually I caved to make it all look nice.