Basically I have now but myself a grow box, its about 50" tall and 30" square. It has three cfl bulbs in there each 20 watts at the moment the plant is propped up to be closer to the light, whatâ??s the best distance from the lights? I have measured my plant and it is now just less than 17". I thought that now would be the right time to change the light cycle to 12/12 how long does it take to show sex? Once the light cycle has changed how long approx to the harvest. Sorry for the multiple posts I have now condensed my questions into one post all help gre/app