I have a few interesting data points for cfl and fl bulb fans. After reading some cfl grow threads where the plants suffered from burning if the bulb is too close to the plant, I decided to measure some bulb temps directly. Using a good quality surface pyrometer on stabilized bulbs (on for about an hour), I get 84 degrees F for a 34w 4100k 48" T12, and 104 F for a 14w "soft white" cfl. I guess I now understand why a T12 can be dropped right down into physical contact with the tops of the plant without causing burn, and why any cfl must be kept several inches from the nearest leaves.
StoneMeadow Reviewed by StoneMeadow on . Answers about CFL, HPS, How Much Light... Although I'm still kind of a new poster, I keep seeing a lot of the same comments--many of which are answered an Dr. Khronik's excellent El Cheapo Guide to Lighting. But there are a few things I'd like to add in regard to watts, lumens, cfl, hps, and efficiency and how much light you need. Maybe this should be stickied? Watts have nothing to do with light or growth. Watts measure how much power a light fixture uses to produce light. You can tell how efficient a light bulb is by looking Rating: 5