I created a clone dome with an aquarium. Just cut the screen out of the top and replaced it with seran wrap. Worked but I had to mist the clones several times a day which I dont have to do with my current clone dome.
^ I also mad one out of an aquarium. However mine was of the smaller ones and didnt have alot of air space. So i didnt have to mist mine alot, i only did it once a day. Just that much water should create a humid enviroment.