i dont know much about growing yet so wouldnt know how many plants to fit in 4x4x5, but im growing 8 plants in 4x3x8 sized room and i think im having good results. but saying that im a n00b so i dont know if my plants are looking good compared to others plants. heres a link to pics of my first everhttp://boards.cannabis.com/cannabis-...ever-grow.html grow.