250 De Mh ?

[NewSchool04]

I just upgraded from a 150 MH pendant to 250. How high is everyone keeping their 250 DE's from the water surface? I'm starting out at 12" and lowering it 1" a week. Just to make it clear, I'm measuring from bulb height, not the bottom of the pendant. :)

Mostly acro tank and Phoenix 14K bulb.

[JGoslee]

started at 12" and lowered it to 8" over the past few weeks. My tank is 20" deep.

[want2reef]

I am at 8", glass to surface of water.