Should I add UVB Light?

[Milson]

These are no joke. I just burned the crap out of a plant using one for the first time. I'm pulling up a seat for some Farm wisdom here

Yeah man those are way too strong for my space for sure.

 

[Moe.Red]

Here's the first attempt - had to bring in the expert. We have a few lenses here to play with, just trying things out. ill this work?

If this is acceptable whether we count them on a computer or not, my next trick will be to shoot the right buds. Gonna have to free hand it to get into the tent. I think it is doable. I also think it will be better to shoot with the HPS lights behind the camera shooting down. I may have to turn off the HPS and use external lighting too. I think I can figure it out. I'll just mark the buds with colored string to keep them straight and take pics of the same 10 or so buds every day for the last 2 weeks.

If this test has been done and I'm wasting time, please let me know with a link.

 

[Milson]

Here's the first attempt - had to bring in the expert. We have a few lenses here to play with, just trying things out. ill this work?

View attachment 1105934

View attachment 1105940

If this is acceptable whether we count them on a computer or not, my next trick will be to shoot the right buds. Gonna have to free hand it to get into the tent. I think it is doable. I also think it will be better to shoot with the HPS lights behind the camera shooting down. I may have to turn off the HPS and use external lighting too. I think I can figure it out. I'll just mark the buds with colored string to keep them straight and take pics of the same 10 or so buds every day for the last 2 weeks.

If this test has been done and I'm wasting time, please let me know with a link.

I will play with this and investigate...

 

[sshz]

Did you follow Calif. Lightworks directions?????

SUGGESTED TIMING The SS-UVB is designed to be used during the last 2-3 weeks before harvest, when it can make a noticeable impact on plants. It is suggested to run your SS-UVB for 2-6 hours per day at 36" above the plant. If you're unable to mount the light at 36" above your plants, decrease the amount of exposure time. Do not power your SS-UVB on during your dark period as this can cause unwanted effects. Always monitor your plants to make sure you are getting the desired response, while making any necessary adjustments in height and/or on time to increase or decrease UVB exposure as desired. Growers typically see a noticeable difference in the amount of trichomes within the first two days after running the SS-UVB for just a few hours per day. Many growers also notice leaves changing color in response to UVB exposure. S

 

[Moe.Red]

These are no joke. I just burned the crap out of a plant using one for the first time. I'm pulling up a seat for some Farm wisdom here

Can you tell me more? I'm putting 80 watts over a 4x4.

 

[sshz]

I should also add that many people start slowly, maybe 20 minutes a day and work there way up from there........something like this:

Day 1-3 20 minutes

Day 4-6 30 minutes

Day 7-10 1 hour

Day 11-14+ 2 hours


Much of it depends on how close the bulb is to the plants. Closer than 36 inches, use less time. Further away, add more time. Plants will need to acclimate themselves to the UV-B, it takes some time. I'll be using them for the first time in weeks 8-10 so check out my "Candy Store" thread in a few weeks.

 

[sshz]

Can you tell me more? I'm putting 80 watts over a 4x4.

The bulb he used is only 24 watts, and he still burned them. 80 watts is wayyyyyyy to much to get results, you better keep them HIGH up or you'll be in trouble. UV-B is very effective, you don't need a lot of watts to do the trick.

 

[Moe.Red]

I should also add that many people start slowly, maybe 20 minutes a day and work there way up from there........something like this:

Day 1-3 20 minutes

Day 4-6 30 minutes

Day 7-10 1 hour

Day 11-14+ 2 hours


Much of it depends on how close the bulb is to the plants. Closer than 36 inches, use less time. Further away, add more time. Plants will need to acclimate themselves to the UV-B, it takes some time. I'll be using them for the first time in weeks 8-10 so check out my "Candy Store" thread in a few weeks.

Thanks. I'll be sure to check it out but please tag me in if I miss it.

 

[sshz]

I will also add the pic in post 122 shows the plants has quite a ways to go, by looking at all those white pistils. I'd say he probably has a month to go, and probably started the UV-B too soon. The plants need to be finishing off, not still be in a growth stage.

 

[Moe.Red]

The bulb he used is only 24 watts, and he still burned them. 80 watts is wayyyyyyy to much to get results, you better keep them HIGH up or you'll be in trouble. UV-B is very effective, you don't need a lot of watts to do the trick.

Yeah dude, I fried plants with these bulbs before. Maybe I should just run one bulb. Hmmmmm. I wish I knew how many uW/cm2 we need, I could just dial in my system to that number.

 

[Moe.Red]

I will also add the pic in post 122 shows the plants has quite a ways to go, by looking at all those white pistils. I'd say he probably has a month to go, and probably started the UV-B too soon. The plants need to be finishing off, not still be in a growth stage.

Yes, it does have a ways to go. Not the target bud - just setting up the equipment on a bud on the side pushed up against the tent.

And no, UV is not on yet. Still getting set up to start here.

 

[sshz]

Yeah dude, I fried plants with these bulbs before. Maybe I should just run one bulb. Hmmmmm. I wish I knew how many uW/cm2 we need, I could just dial in my system to that number.

This video may have the numbers you are looking for........ or you can ask California Lightworks for some guidance.

 

[Pondracer]

I should also add that many people start slowly, maybe 20 minutes a day and work there way up from there........something like this:

Day 1-3 20 minutes

Day 4-6 30 minutes

Day 7-10 1 hour

Day 11-14+ 2 hours


Much of it depends on how close the bulb is to the plants. Closer than 36 inches, use less time. Further away, add more time. Plants will need to acclimate themselves to the UV-B, it takes some time. I'll be using them for the first time in weeks 8-10 so check out my "Candy Store" thread in a few weeks.

Just so you know, I am running a 50w LED bar from Mammoth, 6 hours per day, right at 36-48 inches from 4 plants and they never show any negative effects. Roasts the crap out of any bugs though. I start mine 4 weeks after flip.

 

[Milson]

Just so you know, I am running a 50w LED bar from Mammoth, 6 hours per day, right at 36-48 inches from 4 plants and they never show any negative effects. Roasts the crap out of any bugs though. I start mine 4 weeks after flip.

That's the same level as the full spectrum bars, right?

 

[Pondracer]

That's the same level as the full spectrum bars, right?

I don't know, its this one. https://mammothlighting.com/products/uv-bar

 

[Grownsince95]

@Moe.Red because of my setup and tent etc I wound up just running it waaaaay too close at about 24" on one side of the plant, trying to angle it across the tent under my light. At 30 min a day after a week she was toast. I turned it off until I learn better.

Side closest to the uvb

Far side

Close up of the damage

 

[Moe.Red]

Just so you know, I am running a 50w LED bar from Mammoth, 6 hours per day, right at 36-48 inches from 4 plants and they never show any negative effects. Roasts the crap out of any bugs though. I start mine 4 weeks after flip.

Man that's a nice ass-light. (XKCD)

What can you show us about your grows?

 

[Moe.Red]

@Moe.Red because of my setup and tent etc I wound up just running it waaaaay too close at about 24" on one side of the plant, trying to angle it across the tent under my light. At 30 min a day after a week she was toast. I turned it off until I learn better.

View attachment 1105954

Side closest to the uvb

View attachment 1105955

Far side

View attachment 1105956

Close up of the damage

View attachment 1105959

They sure are fuzzy. Is that a bubble bucket or some sort of automatic water system?

 

[Grownsince95]

I

They sure are fuzzy. Is that a bubble bucket or some sort of automatic water system?

It's an automated dtw high frequency coco/perlite setup

 

[Pondracer]

Wow thats a trip. I have mine setup about the same angle and over vertically. MIne runs down the middle but the plants are offset. This distance looks very similar. I was being conservative at 36", they are closer than that in several places.