CFL distance to tops (did search)

[MrHappy]

I have 12 cfls of various wattages (mostly blue spec for flowering) i am just wondering about the best distance to the plants.. i had them as close as possible .. maybe 1 1/2'' - 2'' but i noticed that it was just too hot and growth got to a point and was halted.. they are now about 10'' away will this be fine?

MrHappy Reviewed by MrHappy on 04-16-2008. CFL distance to tops (did search) I have 12 cfls of various wattages (mostly blue spec for flowering) i am just wondering about the best distance to the plants.. i had them as close as possible .. maybe 1 1/2'' - 2'' but i noticed that it was just too hot and growth got to a point and was halted.. they are now about 10'' away will this be fine? Rating: 5

[stinkyattic]

The reason you can't find a good answer is because it's not written in stone. The right distance depends on CFL size, the heat that particular bulb gives off, your ambient humidity, and how much exhaust you have.
10 inches is too far though. Get the lights as close as you can before you see signs of heat stress, whcih is leaf edges curling UP slightly.

[the image reaper]

I used 48" fluorescent tubes for a long time, and always held them to about an inch above the tops of the plants (that is standard procedure with tubes) ... recently, I built a 'starter cabinet' with an 85-watt blue spectrum CFL ('supposedly' 500-watt equiv. :wtf ... what a surprise ... even at 6"-8" distance, my younguns don't stretch, and seem 'shy' of the light ... the CFLs obviously have much more concentrated light, requiring more distance :jointsmile:

[andrettyy86]

Its to far away

[dopeedogg]

yeah usaually like 2'' maybe 3'' is good.

[killfrenzi]

yeah usaually like 2'' maybe 3'' is good.

Yeah start with 2-". If you start to see signs of heat stress. Start backin off