Question
Maybe you help me out, because I've been to SO many other sources and have gotten nowhere fast.  I've got TWO 2-foot fluorescent tubes.  Packaging says they are 17 watts each and are equal to regular 75 watt output.  Color temp. is 7600k each.  How many lumens do they produce or how can I calculate this to find out?  I'm becoming frustrasted and don't understand why it's so hard to find a direct answer to a seemingly simple question!

Answer
Hi Keenan,

Usually the lumen output is on the sleeve on the tube.  It sounds like your tubes are for reptile use, and they are concerned with color temperature since that will give a better idea of the UV output for lizards.  Unfortunately, plant growers need to know more about intensity (lumens).  From what I could find, your tubes are around 900 lumens.  At 17 watts they will be similar to aquarium tubes.  They would be fine for lower light plants such as Mexican butterworts, Nepenthes, and Drosera adelae.


Good Growing!

Jeff Dallas
Sarracenia Northwest
http://www.cobraplant.com