The tall plant has grown over an inch a day. My worst fear was it would grow taller than the light bulb, and it did. However, the light box and the plant seem to be doing just fine without having the plant right under the bulb. It almost seems to be growing away from the light. The lighting is not like the sun, because the light is reflected around the box and that seems to bath the plant in light from all directions. All seems good as far as light box size. The other shorter plants are gaining a lot of buds, also. I am anticipating the tallest plant to blossom soon because the tips are getting more yellow, and the tight clusters of bud have spread out and develop longer stems.