Some manufacturers put the Kelvin temp info on the CFL bulb or package, but it seems like most don't. It's enough to drive a person nuts. Plus the confusing terms: "cool white" or "warm daylight". If you don't see the Kelvin temp number, you don't know for sure, otherwise, they all look alike to me....:stoned:

6500K=veg
2700K=flower

They do better with Floro tubes.
Dutch Pimp Reviewed by Dutch Pimp 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