Quote Originally Posted by sck202

I think the rule of thumb on distance is if your hand can't stand it, neither can your plants.
Second that....

If you can get your temps down, you can get your light within 18" before bleaching starts to occur.... The easiest way for you to get the temps down where you currently have them is to get some ducting from a hardware store and extend the A/C vent in that room right over your lamp so it cools better....just open the register and measure what size the ducting is so you can get the right size.... After you extend the duct, you close other registers in the house so that more air is pushed to the one left open, i.e. the one you extended....

Also, get yourself some reflective material to cover the sliding doors....lumens are being lost....

If possible, run the extended ducting down to the plant level and hang that fan above the lamp pointing away as you have it in the pic.... This way the new air from the A/C vent should flow out, up passing the lamp, then pushed away from the space by the fan hanging above....just be 100,000% sure that it won't fall or get loose.... You can even leave the restroom exhaust fan on too but I'm sure you already thought of that....

Once you have to funds, air cooled hoods and inline blowers are awesome to control lamp temps....

Hope this helps....

CGI::::::