It sounds like youre trying to set up a shotgun fruiting chamber for your cakes which can still work pretty well without any bottom holes as long as you have them all around the sides. You could also benefit from placing a small fan in the room. With this kind of setup, its necessary to mist several times a day in order to maintain the proper humidity. Monotubs are still the best way to go unless you have a greenhouse setup but if youre not trying to buy a PC (highly recommended) youre basically limited to pf cakes