Sorry for throwing you guy's off about the height of plants .Im gonna flower plants at 1ft 3inch's and hope it will only double and then some.(Also plants now are only 4-6inch's im just getting my sutff ready ahead of time)So hopen between 2ft and half tall to 3ft tall.But when i was at hydro shop.I just thought id go and dish out 135$ for a 250 mini built in ballast hps with some kind of expencive bulb .Like 50 more dollars than orginal one.Hope it makes my plants yeild more