Yes and no. Depends on what your doing....Commercial size = NO! To much work and added electrical costs for the result.
Personal to Caregiver size....Can be good.....
You must remember that with "reptile" bulbs. Your effective distance of UV is only 18"!!! Anything over that is simply wasting your time and money overall.
I did in depth UVB testing some years back.....Lord, somewhere in here is some detailed info I supplied someone else with...2-3 years ago I think....search using my board name,,,I covered Thc % increase by testing using various methods of UV delivery....If you run a MH bulb with not glass in the hood. You do get a measurable effect! Yes ttystick is correct that the secondary glass blocks the bulk of UV from MH bulbs......The glass is borosilicate and that is the same glass in your windows and your light hoods. It is made to block UV.
I did find that 400w Mercury vapor bulbs emit much higher levels of UV across the board! So much that you MUST limit distance from the plant and exposure times! Those too are listed in my UV post that I directed you to search for....VERY complete info on it there. I would ware effective eye protection when in your grow if you try MV bulbs!!! it's that high of an exposure level!
But, yes....UVB exposure not only increase's potency....It changes the type/style of buzz too.....Deeper and more intense - longer lasting! How can you complain about a whole 4+ point (3 - 3.5 is average) shift up in overall Thc levels with well applied exposure!
I still do have the capability to employ the MV bulbs in my new personal facility.....This has motivated me to get those out on the next run and have some fun playing with that again.....Mmm, I feel more stoned already.....
Doc
P.S. I might look for that post and link it if I can find the time.....have trouble finding it sometimes..
