Shoot. I just noticed...You're using four foot fluoro tubes, right? There's a huge difference between cool tubes and fluoro tubes. Cool tubes are clear, tube-shaped housings for HID bulbs with an airflow to remove much of the heat.

If you keep a fan on the plants, heat from the lights is rarely an issue for fluorescent tubes. The closer the better, but obviously keep an eye on the plants for burn spots or stress.

Light from fluorescent tubes are only effective within 4-6 inches, depending on wattage. Reflected light hits the reflector (or wall) and bounces back to the plant. If those two distances added together are greater than the maximum effective range, the reflected light isn't doing anything for the plant.
For instance...if the reflector is 1 inch from the bulb, but the reflector is 5 inches from the plant...you are at your (approximate) maximum distance away from the light. (5+1=6) The same goes for walls and Panda Film stuff.

But if the reflector keeps the light out of your eyes, then I guess it could be a benefit. :thumbsup:

For better results, you'll want lights with more 'oomph' for flowering.
Rusty Trichome Reviewed by Rusty Trichome on . Purple stem problem What is your experience level? Second grow Your Equipment: .1) Type and wattage of lights. ( tube fluorescent) .2) Distance from tops? 2-3 inch .3) Reflector type? ( 4 foot standard fluorescent dual tube .4) Is there a consistent fresh air supply? Yes .5) Do you have an exhaust fan and a circulation fan? Yes .6) What are the bulb wattages, kelvin ratings, and schedule? total 185 watts Rating: 5