currently have a 2 foot by 6 foot and about 8 feet tall space that is set up for venting, and pully system. Question is im only looking at growing 4 plants or so for personal use and wondering how much lumans i need. if 10000 is the best for flowering than is it possible to use like 6 four foot mixed spectrum tubes instead of a HPS? how far should be plants be spaced apart and will it better to have less space if i use the tubes?