Since I’m going to start growing again, I wondered about UVB supplementation. I used to run just a single bulb in the corner of the tent, and it seemed to help, but I’m wondering now if it would be too much to have 4 bulbs on each corner of the tent, or would that be way overkill.
I fall back upon this golden classic, a video when I learned about UVB supplementation.
My last grow I used a 28w uv led bar on the wall of my tent and had great results. I just added a 315 cmh which produce a bunch of uv, so I might not use it this time.
My idea
I use the “tropical” reptile uvb bulbs set at the rated distance for reptiles from the plants. No burning from them, but not sure if it helped since it was my first grow in 12yrs. The reading I did on these led bulbs I’m using didn’t have any mention of uvb supplementation and they still grew really frosty buds. 
A lot of people claim “ bro science “ I call it just plain Jane science . Got these on stand by waiting for flower .
Another thing I wanted to check was, having the UVB lights only run for a 3 hour period during the middle of a 12/12 cycle, kinda like a “high noon” effect.
(edit: cant post anymore for 24 hours due to new account post limit.)
@anon93244739 that 28w UV light I dont think works. The one you have is a black light, which doesnt hit the right spectrum for plants (UVA-UVB).
Upon looking into black lights, they are only in the spectrum of UVA and dont include UVB, which could cause a sunburn. (https://www.hunker.com/13412718/difference-between-black-light-uv-light)
(edit 2)
Reading further into it, “Cannabis plants have their own similar system of blocking damaging UVB: increased trichome and cannabinoid production (CBD, THC, and many others) coupled with increased terpene production. These natural sunscreens are produced with exposure to both UVA and UVB light, although only UVB damages the plants’ DNA. UVA is the safest and least likely to cause adverse damage in plants while still triggering this photomorphogenic response.”
https://www.solacure.com/365.html
I really like these ones. Ill have to find the paper where I read this… but trics act both as an anti-predation and also a “sunscreen” for the plant. So if you add more UV, it produces more trics to prevent harm to the plant. Granted… if you add to much, youll fry it lol.
Yeah, they noticed it in the higher elevation grown plants. That they had more trichromes… then went, well there’s a ton more uv here, wonder if there’s a link. I’ve been doing uv supplementation of some kind ever since I started.
Isn’t UBV also good for Mold/Mildew prevention? I bought a couple of UBV to be used as a Germicidal tool. SS/BW…mister 
Isn’t that uvc?
Indeed, corrected, SUPER Thanks!!! SS/BW…mister
Here’s the exact one I got. Its 395-400. I did get frostier buds when I added it though. Maybe I just got better at growing 
Solacure has good info about using UV lights with cannabis and a bunch of other stuff.
All sorts of other uses on their How-To page as well.
I’d like to get this 4 pack of T12 tubes for about $80 off. I have a couple of 4ft single fixtures so don’t need theirs. They have T8s too. 2 and 4 foot in both sizes too I think.
These are the real deal if you want good UV and sell for US or Canada.
I just blew what the tubes would cost on other grow gear today so the UV will have to wait a bit longer. 
this was around when i was growing up, one of the MC’s in my area ran blacklight on there grow, that was in the early 70’s
What should I buy for a 4*4 to supplement? Running custom lights from bridgelux gen 2s. Any help is appreciated
Honestly, I’d go with my setup on post 3 of this thread, it’ll be the cheapest route. 4 hoods 4 bulbs 3 feet away on all 4 corners. Once you start getting used to it, you could invest in a more expensive setup
Edit: run for 3 hours a day on flowering (mid day)
What’s the more expensive set up? 
I cant remember the brand, it goes for 1799$ and its a uvb led ballast with white light. Uvb chips are very expensive and there are only like 3 brands that carry true uvb led chips. They are over 1000$ and the price goes up from there.
Geez haha yeah. I greatly appreciate you telling me the cheap option haha!
I wonder if there’s some kind of light strips I can diy. Im greatly interested
