How far to keep a 400w MH from seedlings?

[deadkndys]

[FONT=Arial, Helvetica, sans-serif]So I was wondering how far I should hang a aircooled 400w MH from some seedlings? [/FONT]

 

[pcduck]

What I do is place the back of my hand at canopy level. I then lower the light till I feel the slightest heat from the bulb on the back of my hand and that is where I set the height at. Seedlings I would move up a bit further as not to cook them.

 

[WeedHopper]

[FONT=Arial, Helvetica, sans-serif]So I was wondering how far I should hang a aircooled 400w MH from some seedlings? [/FONT]

I wouldnt waste that much power(money) on seedlings. Try T5s or a few CFLs.

 

[trillions of atoms]

x 2 for the win!

 

[YYZ Skinhead]

What I do is place the back of my hand at canopy level. I then lower the light till I feel the slightest heat from the bulb on the back of my hand and that is where I set the height at. Seedlings I would move up a bit further as not to cook them.

:yeahthat: I run HPS but this is the best distance test with any light.

 

[trillions of atoms]

Look at the plants.. They will tell you when the light is to low or stretching because it's to high.