Give them a while longer, they will fatten up some more yet. Once those white hairs recede and start reddening off and you notice a swell in your calyxes check your tric's. You want as close to mostly cloudy you can get. Make sure you are checking the tric's on the buds, not your leaves!
Those are definatly on the right track, but not quite ready, follow what the others posted above and don't forget to add-in 1 week or so to flush your plants daily. Very important .