Right. Maybe 18 inches for a 400 watter, but a 250 watter you could get to maybe 8-10 inches safly. I ran 175 watt MH and it was about 6 inches away from the tops of the plants with no problems whats so every.
That's all I ment, there is no steadfast rule 18".. it could be 18", with a larger light, but with the 250 I have at about 8 inches away...
even a 600 in a cooltube can get alot closer than 18".
It's all good, he likely got that off Mr.Greethumbs: I grow Chronic, I know he mentioned that distance in there a few times, but he also explained the rest about putting your hand under the lights and you could lower them.
On second thought, that may have been one of Jorge's videos... actually, I think it was, I can picture the scene in my head..
I don't like correcting people, but when it's wrong, it's wrong, hopefully the dude I corrected will take it as such and not just think I'm being a dick... which I am, more often than not, but I'm not being one right now.