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plant distance from HID bulb

S

stevie

Hello,
 
I have a 250W MH bulb, iirc it's around 21,000 lumens. i also have a 250 HPS bulb, but i'm looking for small compact plants and from what i gather HPS tend to cause plants to strech more.
anyhow, i'm wondering at what distance to keep the bulb. i realize closer is typically better.. but currently i have the plants (about 3-4 weeks old, 6 inches tall) set for around 16 hours light. i notice that after around 13 hours the plant goes from being nice and perky to droopy (not wilting from lack of water).
 
i have the fixture about 20 inches and was thinking of going a bit closer (around 15-16 inches) but im wondering if they are getting too much light or is the droopy leaves normal after 12+ hours of light? i wanted to give them at least 18 hours, but im afraid they'll just droop down further.
 
temps are good (about 80ish) and i have good air flow so it's not heat related.
 
i'm also growing them hydroponically DWC with air stone.

thanks.
 
Why would you decrease the efficiency of a lamp with mirrors?
 
Every time you reflect light, you loose some.
 
a flat white painted surface is far better for reflecting / difussing light. shiny materials and especially mirrors will focus the light creating hot spots that can definitely burn / harm your plants.

when my seedlings where at the same stage as yours they were under a 400W HID with no damage or wilting. your plants just need to be properly acclimatized to the light, start with the fixture about 2' or more away and gradually lower it a couple inches atva time over a couple weeks.

a 250W ( or 1000W, for that matter ) HID has nothing on the sun, proper acclimation is the key.

HTH
 
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