VegasWinner
Well-Known Member
I would lean towards more uva
UV led?. should I or just add more cob?
- Thread starter HolyGhost23
- Start date
MadButcher
Well-Known Member
What are you basing that on?
VegasWinner
Well-Known Member
there are studies out there that suggest uva is a better choice for plants while uvb is better for reptiles may not be the best choice for plants. uvb is source of sunburn while uva is more invisible lower frequency than uvb.
http://www.mouser.com/ProductDetail...sLkvy3gtd%2bvUIw4NQHmzX1pbvCPe1PvYGJErHHoJQgF
MadButcher
Well-Known Member
So the Agromax folk have it backwards then. Are you basically saying I could just add some blacklight tubes?
VegasWinner
Well-Known Member
I posted an led for grow lights above which has the spectrum desired. I hate when people try to change my words. I said you have a uvb bulb for reptiles not plants. Just pointing out the obvious. The led in the link is not cheap, but more appropriate for what you are attempting. reptile bulbs are not the best light frequency, uvb for plants uva is the better choice. you are free to choose as you wich, you asked my opinion, and I gave it freely and as opne as I could and even provided a link to an led that does what you want to do. a model 3532 will work best cost $14.00 each ->http://www.mouser.com/ProductDetail...sLkvy3gtd%2bvUIw4NQHmzX1pbvCPe1PvYGJErHHoJQgF
MadButcher
Well-Known Member
I don't want to do anything, it's not my thread. I just asked a question which I figured you would know the answer to. No more, no less.
Thank you.
@CobKits in the 'Results' of that study it stated "Only the Delta9-THC content in leaf and floral tissues of drug-type plants increased significantly with UV-B radiation." ...are the floral tissues they are referring too, the flowers that we smoke? if so, isnt that increase a positive thing for UVB?
Danielson999
Well-Known Member
Here's a link to a few studies on why we want to use UV-B in our grows.
List of UV-B Radiation Effects on Cannabinoids & THC Studies
List of UV-B Radiation Effects on Cannabinoids & THC Studies
MadButcher
Well-Known Member
You mentioned those reptile lights. Any idea about distance to the canopy? Or can they just be hung in a tent somewhere ?
Danielson999
Well-Known Member
It would depend how you use them. If you leave them on for the entire daily light cycle then nowhere close to plants. If it's on for short periods (15-30min) then they can be much closer. I've seen some use them as side lighting so their main light doesn't block them. It really depends on your bulb, the repti type bulbs can be 5% and 10% strength. I think in nature at least 95% of uv-b is blocked from reaching us so it makes sense that a 5% bulb could be on your entire light cycle from a foot or two away but it's area of effect isn't going to be huge either. In a 4'x4' tent some people use multiple small bulbs like that.
If you use the agro-max uv pure bulbs that emit 75% uv-b then you could do some serious damage in short order. That's why people use them in short bursts but like everything with growing, it comes down to you watching your plants reaction and going from there. If you hung a 5% repti-bulb up in a corner of a tent it will probably have almost no effect whatsoever. 4 of them in the corners run your entire light cycle probably will though. It's tough finding definitive test results about this subject...
MadButcher
Well-Known Member
Cool! I'm now debating to get me two of those and hang them between my two fixtures. That should help
Danielson999
Well-Known Member
From everything I've read it appears that using 5-10% of your total light output is appropriate. So if your light is 400watts, using 40w of uv-b is about right. Just have to dial in the distance and duration yourself.
Here's another very interesting and short article.
Last edited:
MadButcher
Well-Known Member
Sounds simple enough! Thanks!
captainmorgan
Well-Known Member
It's best to put UV on a separate switch or timer so that you can turn it off when you are in the garden.
Los Reefersaurus
Well-Known Member
As I said I would here is an update. I have had 4 burn days of the 10k bulb over my finishing plants. I took them down today and I can tell you that the flower material seems to have greened up a bit, the buds seem more solid and deep in the buds seems better, there were a couple of plants that lived a much harder life then my normal runs. Working around them figuring out lamp heights brushing up against them generally being a really Pain in the Calyx to them. Anyway, they looked weak and prone to pail centers and or mold from looking at a distance. But no, dealing with them upclose and personal, other then dealing with dead leaf matter, the plants seemed vibrant and much better than I originally thought . About crystal content....... maybe....... I don't know too hard to call. I am am moving the light over to the next group that is finishing in 13 day so we will see what a couple of weeks of 1 hour a day does compared to 4 tanning sessions.
Over all , promising
Over all , promising
Last edited:
@VegasWinner are there any options to connect a T5HO fixture(for my UV's) to an arduino type controller i.e. storm x, hurricane, etc. to control the on/off functions? was going to start with 15 minutes on out the hour for 4 hrs during the last few weeks of flower and dont want to incorporate those janky mechanical timers if i can stay timer-less running the rest of my cob light fixture with just the controller and a relay...
