400 w. New to the HPS game ??!!??

coming from the CFL sub forum. SO i have the undersanding that.. the closer the light the better..

But i just upgraded to a 400 w HPS system. So now...


How far should this light be from the girls when on a 12/12 cycle????

i would say 12inch at least they get super hot HTH

sry, but i cant find the link for the guide but if u click on this thread below, there is a guide on 1 of the posts on how far ur light should be for optimal resaults.. i think its on the last page but could be wrong.... the post was made by "ludacris" and its the thumbnail attachment pics.... cheers
https://www.rollitup.org/newbie-central/230577-pleeeeease-help-4.html

sogbunn said:

heres a guide for ya

Click to expand...

where? what?

12 inches?

Freedom Fighter said:

where? what?

12 inches?

Click to expand...

hey sry... i jus posted b4 i gave u the guide that way i can go bak and find ur thread a lil easier for i didnt have it on hand and had to find it... its up there now

Freedom Fighter said:

How far should this light be from the girls when on a 12/12 cycle????

Click to expand...

My 400 Watt light is air cooled and I am able to keep the tops within 8 inches of the bulb. I use the hand method, put your hand at the same level as the plant tops, if its uncomfortable for your hand then the light is too close.

jrp677 said:

My 400 Watt light is air cooled and I am able to keep the tops within 8 inches of the bulb. I use the hand method, put your hand at the same level as the plant tops, if its uncomfortable for your hand then the light is too close.

Click to expand...

without air cooling I'd start @ 18" - especially if the plants are coming from a CFL environment - then gradually move it closer until it's 12" or you see leaf tips burn. Then back it off. Be careful

thanks guys. it not air cooled.. nice light Jrp. mines just a bulb and a wide hood so i'm assuming it will get pretty hot. Ill be starting it around 12-16 inches ... but we're in agreement?.. 12 inches is the min distance it should be?

Agreed! 16" would be a good starting place and then work down as far as you can. Good Luck!

I would start with it at 18" unless air cooled! I have cooked my plant's off A 400 that was not air cooled, so be careful and they will tell you when to stop!

well I'm probably the minority here but mine is about 8" from the tops not air cooled.. but I have a good AC setup..as others have said use your hand if you would not like your hand that close for 12 hours your plants wont like it much ether..