does it matter how long grow lights are

[ladyslipper]

Hi guys, would it be better to have longer grow lights over shorter ones? What I mean is does the light emitted at the ends of a grow light substantially reduced over say, in the middle?

regards, m

[aquanut415]

the longer the bulbs the more lumens compared to shorter ones. its not a huge difference, but the longer bulbs are brighter.

[Oscarman]

The light intensiy does drop off substantially as you near the ends of the bulbs, so longer fluorescent tubes would be prefered.

[Ross]

Some t5s are rated to produce constant light over the length of the tube (but I doubt the claims, as the above folks attest). I have best performance with 48" tubes over a 36" wide Orchidarium.

[ladyslipper]

thanks for your replies guys, could I make up for the fact the light drops off at the end of the grow tubes, if I had the stand about 3 ft from an east window that has no shading?
regards, m

[dave b]

Originally Posted by ladyslipper

thanks for your replies guys, could I make up for the fact the light drops off at the end of the grow tubes, if I had the stand about 3 ft from an east window that has no shading?
regards, m

Sure could. A lot of folks keep their racks near/in front windows for additional light. Many times its almost necessary since fluorescents dont give off real intense light. If its unshaded, then the several hours of sunlight coming in each (sunny) day will do great for them.