400w MH - How close?

[Wallykazam]

So im looking around trying to figure how close i can get this light to some seedlings....im not looking for specs on lighting or graphs showing lumens....just a straight answer on how close i can have the light and not do any damage.....its the only light i have and im gonna work with what i have.....so buying new lighting specifically for seedlings is not going to happen! Anyone who has experience in this matter and can give a straight answer without all the scientific mumbo jumbo would be greatly appreciated

 

[Nismo12]

Air cooled - 12" or a bit closer. Not air cooled I would start at 18" and go from there. If they like it you can lower it slowly.

 

[Weaselcracker]

My babies and clones are down on the floor at about 24" away (I'm guessing- haven't measured), but the bigger veg plants grow within 6" or less of the light before looking at all worried about it. Babies don't need as much light, but the bigger ones practically have to touch the bulb before taking real damage. New hortilux bulb. Not air cooled just a primitive diy reflector

 

[Wallykazam]

Thanks much ....i tried so many different places with no straight answers lol.....got a idea now anyway....much appreciated

 

[thebudking]

Put your hand over the plants, palm down, lower the light until you feel warmth from the light then raise it a little. Hold your hand under it for about 30 seconds to get a good feel of the heat.