HPS question

[Junk_Bandit]

How far away should you keep a 400 watt hps from the plants so that you don't burn them? Thanks!

[the image reaper]

usual answer is 18" - 30", but that changes greatly if you are running a fan-cooled fixture, they can get much closer (you do lose some lumens when air is blown over a lamp, but hardly worth mentioning IMHO) ... I highly recommend fan-cooled lamps, and ballasts usually last longer in cooler environments, too ... :smokin:

[xcrispi]

All depends on the hood and air cooled or not .
Need a lil more info to be of much help . General noob rule of thumb is put your hand right at canopy height , too hot for you = it's to hot for them .
Peace
Crispi :jointsmile:

[Junk_Bandit]

right on, thanks guys!