just another thing .... its just my personal opinion so please don't anybody get upset with me if you disagree ( iam trying to learn to type happy ... sometimes i read my replies and think wow i sound like a dipshit) ... anyway, personally i prefer to grow under HPS than MH ... i find HPS grows a more tighter plant with closer internodal spaces ... MH definately grows them up taller quicker ... but i just find the branching to be more leggy and sparse with larger internodal spaces ... Its been awhile since i done a side by side (same enviroment, segregated light source)... maybe i should do a more recent one and prove myself wrong ....