How far does my light need to be from my plant ?

How far away does my light need to be from my plants , right now im doing 250w MH as they r still in the first few days. Will switch over to 400w HPS once they become a bit stronger. But how far does the 250w MH need to be from now and what about when i switch to my 400w HPS (cos it will be hotter of course and the plants much bigger)
I keep my tent doors open with the window in the room open and fans blowing from all directions so I stay at around 25-27C right now (75-82F).

Thanks for any help guys.

P.S. I did get YoYo's (easy rollers) .

PetFlora said:

You did not provide enough info, plus photo would help. Clones, seedlings....? Based on no info I would say ~ 2ft for young seedlings, ~ 18" for young clones

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well really just in general any information about how far does the light need to be , but im guessing around foot and half throughout the growing?

I found my own answer , its around 1 foot and half. for anybody that needs to know.

It is really dependant on the heat output of your light... For example I keep my 1000watt hps approx 16-19" away from the tops of my plants, but my 400 watt mh is literally 3-5" away from the tops of my plants. The rule of thumb is to place the light as close as possible without burning the leaves... air cooled tubes.. booster fans.. inline fans, and oscillating fans will all help disperse the heat away from your lights... thus allowing you to really hug your light up to your ladies! Hope that helps

Dice Clay said:

It is really dependant on the heat output of your light... For example I keep my 1000watt hps approx 16-19" away from the tops of my plants, but my 400 watt mh is literally 3-5" away from the tops of my plants. The rule of thumb is to place the light as close as possible without burning the leaves... air cooled tubes.. booster fans.. inline fans, and oscillating fans will all help disperse the heat away from your lights... thus allowing you to really hug your light up to your ladies! Hope that helps

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Thanks but I got 5 plants in total for a 3x3x6 tent so I think little over a foot is good to get a nice light hug for all . Or ? Using 250w mh right now will switch later to 400w hps for flowering .

As the grower you get to choose... that is what is so great Plants tend to double or even triple their height when flowering.

some people switch to flowering when the plants are only inches high, so to each his own...if you feel they are structured enough then make the flip