what distance should my fixture be from my tops of plants?

[jbuyno96]

I have a 250 or 400 watt mh or hps fixture so i can use any combination of those things. Currently i have a 400 w hps bulb in, and im just wondering if anybody could reccomend a good distance. Im just playing with it having different distances at the time being. Thanks!

 

[Jamison]

Hold your hand above your plants and make sure you dont feel the heat from the lamp. Obviously the closer the better. Thats all i do with my 400 watt hps.

 

[jbuyno96]

Hold your hand above your plants and make sure you dont feel the heat from the lamp. Obviously the closer the better. Thats all i do with my 400 watt hps.

Thank you! Would you know why certian leafs have small yellow spots? Nothing i see online is similar

 

[Jamison]

Your welcome!  Would have to see a picture to give you an educated guess!