Can You Use Black Lights?

Do Plants grow well under black lights?

no.


.........

years ago High Times did a article about this. They ran them during the night cycle i believe. The test result seemed to indicate larger but fluffier buds. personally i prefer large tight buds. or small tight butts(female to clarify).....i mean buds... yeah....

no u cant
as for running in dark cycle not worth the cost of power but i guess u could use the low light to care for plants in dark cycle
if i remember right isnt the black lights purple color when lighted?

Plants can't use UV spectrum light for normal photosynthetic activity.

So the quick answer is no, you cannot grow plants successfully under JUST black (UV) lights.

The question is, assuming you're growing under conventional lights, will supplementing UV lights add anything?

Some people think THC is a sort of natural sunscreen and that cannabis plants will ramp up THC production under exposure to UV light, so there might be something to this.

Personally, I don't know if this does or doesn't work, but I'm highly skeptical and my bet is on "not". If you could create a meaningful increase in quality just by running black lights, everyone would know this already, and it would be common practice.

Right on, I would be highly skeptical about running them myself. And Iv never actually heard of anyone doing it, other than that one HT article at least 18 yrs ago.
You would need a actual spectragraph(?) to determine if it even put out any light a nm range MJ can use. then way pros vers cons. Keep in mind there are a few different types of blacklights. some are nothing more than painted glass. And without looking it up, i believe real ones have a certain make up of phosphors and such to produce the violet colored light.

unohu69 said:

Right on, I would be highly skeptical about running them myself. And Iv never actually heard of anyone doing it, other than that one HT article at least 18 yrs ago.
You would need a actual spectragraph(?) to determine if it even put out any light a nm range MJ can use. then way pros vers cons. Keep in mind there are a few different types of blacklights. some are nothing more than painted glass. And without looking it up, i believe real ones have a certain make up of phosphors and such to produce the violet colored light.

Click to expand...

wonder if it recognizes purple light i know it doesnt green if not make great lights off work light

if you go here:
https://www.rollitup.org/indoor-growing/358190-led-without-leds-my-first.html

and check out the info there, you will understand color spectrum a lot better. and the fiji purple bulb professor recommends is well, really purple......
just something to think about.

also, i dont think there is really a purple light, i think thats just the way the human eye perceives a it to be.

unohu69 said:

if you go here:
https://www.rollitup.org/indoor-growing/358190-led-without-leds-my-first.html

and check out the info there, you will understand color spectrum a lot better. and the fiji purple bulb professor recommends is well, really purple......
just something to think about.

also, i dont think there is really a purple light, i think thats just the way the human eye perceives a it to be.

Click to expand...

well im a hid man myself
but need a light that wont wake up girls guess i will have to just let them bastards at the hydro shop rip my wallet out of my back pocket
mostly likely will tear the pocket of too

I hear ya, a lot of people run hid's. i have some smaller ones going myself. however, my understanding of the problem with MH/HPS is they only produce a small percentage of light in the useable range of MJ. sure they are bright, and thats what they have going for them, you can produce more of the correct spectrums with the Floros if done properly.

So in a sense, a 1000w HPS light is actually only producing about 200watts of usable light. not perfect math, but just making the point.

Good Luck. we all need it.