i have a 1000w mH light im about to hook up. ill be putting ten clones under it. at what height should i hang the light.?? and how should i know what the perfect height is. hand test maybe?????? thanks guys.
Hand test it, start out an 18 in above them an work em up as they get bigger.
You also can get a conversion bulb to run a HPS in the MH ballest for flowering.