UV-B When and How Long Are You Using It?

So I recently purchased two California lightworks SolarSystem UVB lights to run over my 4x8 grow table.

I already have a pretty good idea on how I want to run them, 24-36" above the canopy for about 2hrs a day on for about 10 minutes per hour during my entire flower cycle.

Obviously I am not going to start at 2hrs a day but work them up daily till I hit that number. Maybe start at 12x 1 minute cycles and adding 12 minutes/day till I hit the 2hr mark.

However I am new to this but like everything else I do, I research the hell out of it and in doing so, I am curious to see how my fellow growers are using them in their grows.

How are all of you using yours?

I use the same uv lights. Have tried them many ways but settled on 30min per day at peak of day. Have been only using during flower after bud set. At the end of flower during the ripening add another 30 min after an hour off.

Was using it during veg but did not see a great benefit to wasting the bulb life.

This is what has worked for me to see more trichrome and feel a more potent effect.

My results are purely subjective as there was no lab testing and I'm relying on my best stoner observations and sensory perception.

I'm wondering what the first signs are of using too much UV? What does a plant that got too much UV light look like, anybody got some pictures?

This is the maximum amount of damage I let the leaves get from it.

Some people will be offended by the looks of it but I can tell a difference in effect whether it be psychological or emotional or physical. Still has a more potent feel to me.

Also, there is visually a noticeable increase in trichomes, whether it be from coloration causing it to be more noticeable or more numerous I don't know.

This is my observation from running same plant clones. Did not specifically take pictures to label for comparison, just notes.

XtraGood said:

I'm wondering what the first signs are of using too much UV? What does a plant that got too much UV light look like, anybody got some pictures?

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This is shortly after adding the extra 30 min
for a total of 1 hr,, 2× 30 min intervals with 1 hr in between.

The leaves are beginning to get damage which supposedly causes a receptor to react in the plant.


3 weeks later

Sofa King Smoooth said:

I use the same uv lights. Have tried them many ways but settled on 30min per day at peak of day. Have been only using during flower after bud set. At the end of flower during the ripening add another 30 min after an hour off.

Was using it during veg but did not see a great benefit to wasting the bulb life.

This is what has worked for me to see more trichrome and feel a more potent effect.

My results are purely subjective as there was no lab testing and I'm relying on my best stoner observations and sensory perception.

Click to expand...

Yeah, I want to try the 1-10 minutes per hour and avoid the longer "ON" periods to prevent damage. The way I look at it is comparing how humans react to the sun's UV. When I go outside quickly, for a few minutes at a time, I will slowly tan but not burn. If I go outside for longer time periods I start to sun burn.

Basically gonna try shorter, more frequent blasts of UV to try and prevent damage. If I start seeing damage, I will adjust the light accordingly.

I also want to start earlier than later to give the plants a chance to harden off before flowering starts. I would rather damage leaves than buds while trying to dial these things in.

When I first start the uv, I give them a day on then 2 off couple times.

10 mins of the light on bare skin will burn to blister sensitive skin.

I forgot it was on and blistered my ears doing a feed

Sofa King Smoooth said:

When I first start the uv, I give them a day on then 2 off couple times.

10 mins of the light on bare skin will burn to blister sensitive skin.

I forgot it was on and blistered my ears doing a feed

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I was thinking of putting a red flashing light on the same timer as the UV lights because I could see myself not realizing they had turned on and burning myself.

I am shooting for 2hrs a day but could end up doing 30 minutes a day who knows. I am a noob at this. Lol

Something like this.

King Avitas said:

Something like this.View attachment 5108537

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That will get your attention!

One of the newer uv lights came with a little red light on it that flashes when it's on but the lights are above the door opening and I don't usually look up. It hasn't happened since the first time. I pay closer attention to the light schedule now

King Avitas said:

I was thinking of putting a red flashing light on the same timer as the UV lights because I could see myself not realizing they had turned on and burning myself.

I am shooting for 2hrs a day but could end up doing 30 minutes a day who knows. I am a noob at this. Lol

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I tried several variations and settled on this as a basic. Some plants take more. I had one that burned with 30 min

Sofa King Smoooth said:

That will get your attention!

One of the newer uv lights came with a little red light on it that flashes when it's on but the lights are above the door opening and I don't usually look up. It hasn't happened since the first time. I pay closer attention to the light schedule now

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I think it will look cool, kinda like the room is on self destruct and I gotta escape. Maybe I'll dive out the door James Bond style.

There was a recent thread that inidcated at some point the UVB started to degrade cannabanoids. I think it was a thread based on experiments by an Austrailian based company here. One of the site sponsers so you might look in the advertisers section to find it.

Fardsnarp said:

There was a recent thread that inidcated at some point the UVB started to degrade cannabanoids. I think it was a thread based on experiments by an Austrailian based company here. One of the site sponsers so you might look in the advertisers section to find it.

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I have read some material to this effect too and I can totally see how this a true statement. I am not planning on trying to push this light to the max like I do with my grow lights. I am basically adding it to try and boost oil/terpene production. Basically just trying to get a little closer to what the sun does naturally. Like I said 2hrs was the maximum I would consider based solely on the manufacturers literature but in reality, I could end up running it for a fraction of that. It just depends on what I observe when I start playing with it in a few days when it arrives.

This is one that got too much too soon.

Don't remember if it was at 90min or 120min.

Sofa King Smoooth said:

View attachment 5108553
This is one that got too much too soon.

Don't remember if it was at 90min or 120min.

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I would still smoke it.

But yeah, I am sure I will probably cook something before I get it dialed in.

For me this is a hobby. I honestly love growing weed and trying to do what many people do not or cannot do is what keeps me going. With my current set up it would have been considerably cheaper just to buy weed but I just love growing the stuff.

King Avitas said:

I would still smoke it.

But yeah, I am sure I will probably cook something before I get it dialed in.

For me this is a hobby. I honestly love growing weed and trying to do what many people do not or cannot do is what keeps me going. With my current set up it would have been considerably cheaper just to buy weed but I just love growing the stuff.

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With lights and uv especially just have to watch closely and take notes has been my experience.

Growing multiple strains together becomes even more of a challenge with uv so I had to give in and only run clones together to make life less difficult.

King Avitas said:

Basically just trying to get a little closer to what the sun does naturally.

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Don't assume this is 'maximal' for your purposes. Death is as natural as it gets, but...

Sofa King Smoooth said:

With lights and uv especially just have to watch closely and take notes has been my experience.

Growing multiple strains together becomes even more of a challenge with uv so I had to give in and only run clones together to make life less difficult.

Click to expand...

Currently I am running a 60/40 sativa hybrid and a 90% indica together. I shouldn't have done this but wanted a bit of each after I was done my first grow in this new room. I have been buying weed since my last grow room had to be shutdown because an explosion/fire almost 2 years ago.

After this grow I will be doing an all indica pheno hunt followed by a sativa landrace grow so things should be more uniform in my room later on.

King Avitas said:

Currently I am running a 60/40 sativa hybrid and a 90% indica together. I shouldn't have done this but wanted a bit of each after I was done my first grow in this new room. I have been buying weed since my last grow room had to be shutdown because an explosion/fire almost 2 years ago.

After this grow I will be doing an all indica pheno hunt followed by a sativa landrace grow so things should be more uniform in my room later on.

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Which sativa landrace?