The following was received via email: What instrument can I use in order to measure the amount of grow light that I'm using?
there are light meters that will measure in Lumens and/or lux and or virtual comparison to sunlight. some hydroponics stores will have these and probably photgraphy stores. I had one with an attached light sensor , had about a 3 foot wire so you could put it close to a source and have the readout "computer" in the other hand. Try http://www.alliesbc.com/htdocs/pdf/Lighting_V.pdf page 7 for 3 light meters available from Allies Wholesale in Langley BC.
