I am assuming you have 6'x3'x8' (length, width, height). That means you have a 18 sq ft growing area, so you only have a little over 3K lumens per sq. ft. Thats about minimum. If you are planning on growing trees, I am not sure how good light penetration will be as they gain height. Rule of thumb seems to be, as long as you can control the heat, you cannot have too much light, to a point of course.


b0nger