Holy shit man! Those are doing great for your first time around! Those look like sativas ... I would have started the flowering at 14" to 18". Sativas can get up to like 15 feet tall so depending on how long it takes for them to bloom completely.... you might need to cut a hole in your roof...lol or cut the top every so often. Great work though! My first sativa grow was crazy.. shit got as tall as a christmas tree..lol. I now have an indica strain growing which is a little more greenhouse friendly as far as height goes. :thumbsup: