you could attempt to bonzai them to keep the size down, but when you start influencing the plants growth eventually your going to start influencing the quality of bud produced. I agree, with the previous posts this is going to eventually become too small of a space for the plants. Not to mention 10 plants at budding growth just wont happen...maybe 4 or 5. Even at 4 or 5 your going to need C02 injection if it's going to be enclosed or you'll end up with a box of oxygen, and stunted plant growth.