Interesting.. I remember an article in High Times (wayyy back when) about a grower who flowered blueberry hybrids under Metal Halide lamps on a regular basis. His reasoning : The blue/violet /uvb profiles of the MH arc suggested that while the resulting buds were not as big as those grown under HPS light, they were more fragrant (fruity, berry) tasty and potent then those grown under HPS lamps. An interesting theory was also proposed for MV (mercury vapor lamps). This particular article was entitled: "Bring the mountains indoors" and suggested a co-relation between growing ganja @ High Altitudes and increased potency. About 10 yrs ago, I used a small (175w) Mercury Vapor Lamp to grow a "test plant". The light does not put out a great deal of lumens, but the spectrum was a cool white/ blue /violet and the resulting buds (although not huge) were tight, resin-filled and Remarkably Potent
. The test strain was Nirvana's California Orange, which btw had a most excellent frangrance and taste as well.
PS- for anyone who wants to try their own experiment, make Sure you get the Clear bulb, and not the phosphor -coated one