i have always grown 18hours light a day under 400 watt mh for 8weeks during veg stage. then i switch to 400 watt hps 12/12 light for the flowering. i am on a new grow right now of 3 weeks in the veg stage. if i were to go ahead and put my hps on them right now to continue the veg stage, will ther be any damage to my plants other than them getting taller? or is there some reason i dont no of that they need to stay under mh to veg? anyone out there do or tried this before? i sure could use some input. thanks.