Youre only cutting off a tiny portion of the very top of the plant. You shouldnt be removing any more than a pinch of growth if youre topping. And the effects are SOO worth it.
i dunno man, a dude on my journal said they were looking pretty short for being 3 weeks so since im a newb i wasn't sure if it was or not...but i'm glad it's all good and they're lookin pretty sweet...i can kind of get the scent of dankness when i'm checking them out...might be psychosymatic though...lol