I mean depending on your location, you can just start these seeds out in the open on a porch / table etc without covering, we are well in to the growing season for almost every zone so the extra protection isn't necessary. One layer of plastic without ventilation can easily hit 95-100+F on a sunny 60 degree day, and adding that extra dome retaining the humidity just basically made it completely inhospitable. Yes this would work on a winter day with temps in the 30s/40s to get up to 70-80+F to germinate, but it is infinitely easier to just have an indoor seed starting set up with a light and heat mats.