I have rarely pruned fan leaves ever. Rarely I'll find an indica that seems to want some trimming. I do top the plants to keep them from growing too tall and trim lower branches so the light doesn't need to reach those bottom little buds. Keep in mind that even with 1000 watts of HPS the light is not so strong when you get to the bottom of a 6 foot (2 meter) tall plant. And with LED and CFLs the light is even less powerful.