ive got a couple of plants under a hps at the moment, im planning to flower this weekend so there ready before i go on holiday... due to the LST undertaken my plants arent very tall... would it increase yield or decrease yield if i hung the lights about 4 ft from the plants in the hope that they would stretch a bit before i started flowering to increase stem length and therefore possible bud sites, then droped them back down after a week or so...