Sorry forgot to tell you which strains. I am growing skunk1, killawatt, violator, og, and trainwreck. my ph and temps are all in check. I get very little stretching. The lights are placed just above the plants so the back of my hand does not get to hot. I have tried different hights I would guess between 9/10 inches to 20 inches. I am using air-cooled light and have the lights hooked to a large vortex fan that vents through my attic. Even the main coala gets spungey.