you can as long as its not silver solder and you dont need that. i havent had any stretching issues with my leds so far, in fact as long as i keep them in the sweet spot they just started filling in underneath big time. being primarliy indica helps on that tho i can only imagine how much better that would be if i hadnt had ph issues at first. admittedly i have not had any sativas yet. but i think they would be lovin these things.