First time UVB set up - what I did

[Swany]

Ed R. talks about UVB increasing thc production in his bible, which is where I first saw it. I'm sure there are posts here too but I have not searched for them much. I'm posting this in case it inspires anyone, or someone can help me improve it.

I have been very busy and don't have the time I would like to detail this (though that might make it an easier read ;-). If you see something of interest and have questions I get to answering you, or if you would have done something differently and care to share I'd appreciate it.

I first started looking for tanning bulbs, the kind in tanning beds. They are an odd length, arn't easily found in T5, and require special ballasts. I then learned of Lizard Lights. These are UVB lights you hang over pet lizards to supply them with UVB to keep them health. They come in different %'s, i got the 10% UVB T5HO's from Zoo Med, through Pet Mountain.com.

To mount them in my room I rigged a fixture out of PVC and a dual bulb T5HO fixture. In stead of doing a play by play I'll briefly explain. 1/2" PVC to make a frame work to support the lights on either side of my hood. Cut the sides of the metal fixture to drop the pvc into. The wires in the light are not long enough, so I used push in connectors and 18ga wire to extend the wires. Tombstones are the plastic pieces that the pins on the end of the bulb slip into. I pulled the tombstones out of the metal fixture and used screws through a small loop of plastic on the base of the tombstone to hold it in the new reflector. This new reflector is a strip cut from a 5" piece of conduit with mylar surfacing the concave side of the strip. This whole gizmo then sits on top of my light bars with a cord running up and over to a timer. Based on a thread I read on another site ( I'll reference later) I'm running just a couple to few minutes per hour to start. I will build this up over a week.



As you can see in the last shot they take a bit to warm up. The timer is a Titan 9, and I could not get it to work the first night I tried to set it up. I had to hit the reset button tonight, which caused one of the un-explained indicators on the front to wink out. Reprogrammed and it's working now. I am half way through week 6 of bloom, so I am late in getting this implemented. I though I would have half the plants lit such, but I have not completed a second fixture, so I only have 1/4 of the plants lit with UVB. Either way will share any difference I find in the same strain with and with out UVB.

 

[ttystikk]

Fascinating setup! Did you do any research on the intensity of UVB emitted by the lights, and what is considered ideal for cannabis? I've seen one other UVB setup, that was a CFL bulb in a reflector, and it was mounted quite close to the plants, as in less than a foot above the canopy. Chat up Flowamasta, I bet he will have some valuable insights for you.

Meanwhile, I really dig the frame you built to house the bulbs, and I like how the bulbs are arranged to spread their footprint broadly. That's actually changed my thinking, IF you're getting adequate emissions. If you're not- and for my money you're a bit high yet, just an educated guess- then it would be relatively simple to alter the frame so the bulbs are lower. The key would be to do it in such a way so as to avoid interfering with any light emitted from the main bulb.

 

[Swany]

Did you do any research on the intensity of UVB emitted by the lights.... you're a bit high yet

Thanks Tty - What do you mean I'm a 'bit high' yet? This is no place to accuse someone of that ;-!

I did a bit of research. Read though this post on greenpassion.org called Methods for Increasing Potency which I found on a google session. Zoo Med recommends keeping these lights 18" to 36" away from reptiles. I have them 24" or a bit more from the plants and hope that the cross pattern in the middle makes up for the distance increase at that point. Ed suggests 10% uvb wattage as compared to your main light (think I read that in his book). I'm using just that.

I kept the bulbs at the hight they are at for just that reason, not to interfear with the main light. The fixture is easy to modify, just cut and couple a new piece in. I had to do this when I made them 'cause I messed up a measurement ;-} I extend the wires a little longer than needed in case I wanted to lower.

Just to play it safe i'm following a schedule like the one Only Organics tried in the above post -quote-

Day 1 schedule:

7am - hps only
8am - hps only
9am - hps only
10am - 1 minute UVB
11am - 2 minutes UVB
12pm - 3 minutes UVB
1pm - 4 minutes UVB
2pm - 3 minutes UVB
3pm - 2 minutes UVB
4pm - 1 minutes UVB
5pm - hps only
6pm - hps only
7pm - hps only

I will be increasing these by 1 minute each day until I get to the 12,15,17,20,17,15,12 minute intervals.
The plant under the light is vanillia kush and another 'control' VK plant is in the corner furthest from the 15 & 26w UVB level 10 reptile lights.
-end quote-

I have 108 w of 10% uvb, he used (4) 13w/26w cfl's I think. We'll see.

 

[ttystikk]

Sure it is! All the better if it's on your own produce! Lol

I like the setup, and I like your side by side approach. However, in the case that the bulbs are too far away to do much good, how will you be able to know that result from 'just doesn't work for me'?

 

[Swany]

My plan is to increase the uvb nightly and watch to see if there is positive or negative effects as compared to the plants not under the uvb lights. I'll also ping Flowamasta to see if I can get some more info, but I've not taken the time yet.

 

[ttystikk]

I know he'll be tickled to talk to you, lol

In your shoes, I would continue ramping up UVB exposure time until either you see a detrimental effect (leaf burn) or it goes all day. This would be the best bet for maximizing the beneficial effects of UVB, because low intensity can be compensated for with longer exposure time. Low intensity won't burn. That's why I like those long ass four footers, because the light distribution has to be nearly ideally even.

One more thing- you mentioned that the bulbs took time to 'warm up'. Did you account for that warm-up time in your light exposure table?

 

[Swany]

I didn't start the first hour at 1 minute, started with 2 and went up to 5 minutes in the middle. I doubled it just now 4 min, up to 10 min, down to 4 again over 8 timed events. I want to just jump to 20 minutes and hour. I won't cuase even though I doubt I would hurt them, I don't want to take a chance. The experience of the dude above is all I got to go on for timing. You don't want to live in the Pacific North West all winter, then fly down to Mexico and spend a day on the beach without sunscreen. I want to give the plants a nice base tan ;-}

And.... the bulbs had come out of the cold night air and been lit for the first time when I took that picture. They will come up to temp quicker when starting out near 80.

 

[ttystikk]

Kewl- keep us posted! I still think a little research on light intensity would help out a lot. When hardening plants for outdoors, it's usually a couple of days and they're good to go. Guessing this is similar...

 

[Swany]

I brought the UVB up to something like 15, 20,20,20, 20,15,15,12 last night and left it there tonight. This is the 4th or 5th day with UVB. I don't think I see a difference yet.

First two pictures are a Non UVB bud, flash and then no flash. Third and fourth pictures are of a bud under the UVB lights with a flash and then without. Both the same strain and of relative size. Some of the pictures are less well focused than the others. This may be because I'm less focused than usual at the moment, long day...

 

[ttystikk]

Had a chat with flowamasta; he's using a 10% UVB CFL bulb, 16W. He placed his bulb at 6"-12" above the canopy and leaves it on got the whole day cycle. He said the packaging said the light intensity was designed with the 6" distance in mind. He starts the bulb at 12" in height during veg, this equates to about 30% of the intensity at 6". At flip, he lowers it, and observes more weight, heavier trichome production, and is convinced of increased potency.

 

[ttystikk]

Long and short of it is that fluorescent sources of UVB just don't have a lot of intensity- so you may not see any results even with the bulbs running the entire day cycle at the height they're currently placed above your canopy.

I have no idea how you'd be able to get those tubes to within a foot of the canopy without shading out more light than it's worth! Option B might be to use two bulbs everywhere you currently have one?

I remember something about using 10% of the flowering wattage as a guide for UVB wattage. The distance is a critical factor in its effectiveness.

 

[Swany]

Thanks for making the connection with Flowa Tty. I'll kick 'em up to 30 min on and 30 min off for tonight's cycle and then 45 on 15 off and finally 12 hours strait. Sounds like I could go strait to full on now but I still want to ease into it. It's good to hear anothers experience. I don't know the math, but I have 108 watts at about 24 inches which according to the mfg is good....for a lizard ;-}

I don't want to drop just the UVB's cause, as you point out, i'll shade some of the main lights output. With the way the Awings concentrate light in a band below the edge of the wing I would be causing a lot of shading. I'm thinking of switching to a new hood called a Venus. I'm installing some in someone elses room and will check out their spread when we test. I may be more willing to remove the reflector from the UVB bulbs and drop them lower if the Venus hood has a better distribution. Or I could double the wattage....

 

[ttystikk]

I'm thinking more four footers, with reflectors. Area bombardment, baby!

 

[rick ratlin]

Thanks for taking the time to document this action Swany.

I too run the aaw's as my reflector. Depending on the bend of the wing, the highest intensity from the reflector is most likely directly under where you've got your uv bulbs hanging. I'll get light bleaching if I don't rotate plants from that spot, so it may be detrimental to place the uv bulbs there. Just a thought. Anyway thanks again for the documentation!

 

[Swany]

I'll get light bleaching if I don't rotate plants from that spot,

You're quite welcome ;-}

Light Bleaching...? Do you mean the plants actually loose color or are you meaning something like a mild burn. I don't know the term. How much space do you keep between the fixture and the plants?

 

[Swany]

I'm thinking more four footers, with reflectors. Area bombardment, baby!

I have another two bulbs, and bought another 4" drain pipe to cut up for reflectors. Was planning on adding it to the other half of the row that the current uvb lights shine on. It's a good thought to double up the current set up... For two reasons I'm not going to do that yet. One, I won't have the time to build the second fixture in the next week and by that time I'll be getting close to harvest. Second, I'm hoping one set will make a difference. With the current set up extended to all the plants that would add almost 420 watts to the room (auspicious number ;-) and if I double it I would also double the additional cost.

 

[ttystikk]

I have another two bulbs, and bought another 4" drain pipe to cut up for reflectors. Was planning on adding it to the other half of the row that the current uvb lights shine on. It's a good thought to double up the current set up... For two reasons I'm not going to do that yet. One, I won't have the time to build the second fixture in the next week and by that time I'll be getting close to harvest. Second, I'm hoping one set will make a difference. With the current set up extended to all the plants that would add almost 420 watts to the room (auspicious number ;-) and if I double it I would also double the additional cost.

The rebuttal to your logic is in every mechanical engineering textbook; if the solution doesn't work, it's a zero benefit no matter what the cost. Second, if the cost outweighs the benefit, either quit or step up your approach. Third, if the higher cost produces a benefit that will pay for itself, DO IT!

Lastly, an indoor garden is no place to get superstitious. If 840W is all it takes to get results, why would you let that stop you?

 

[ttystikk]

You're quite welcome ;-}

Light Bleaching...? Do you mean the plants actually loose color or are you meaning something like a mild burn. I don't know the term. How much space do you keep between the fixture and the plants?

Light bleaching actually kills leaf surface material. It looks different than a contact scorch, but it is the plant's equivalent of a sunburn.

If your AAW is set up this way, you can either move the bulb up or down to change the focus point, or adjust the spread of the wings to alter the pattern, or both. Properly set up, they should provide even lighting.

The last thing you need to worry about is light bleaching from your UVB experiment. Your light intensities are too low and you're not running them all day. It should only take a few days to adequately garden off plants to UVB exposure.

 

[rick ratlin]

You're quite welcome ;-}

Light Bleaching...? Do you mean the plants actually loose color or are you meaning something like a mild burn. I don't know the term. How much space do you keep between the fixture and the plants?

Here's an old shot of a plant that got some bleaching. This was in a tray left unattended for about a week without moving around.


This was due to poor canopy management, as this plant was about 6-8" taller than the others, which remained nice and green. These were right in line of the edge of the aaw. At this time I ran large aaw's with a 600 watt hps in a cool tube.
About a foot over the canopy.

 

[thescaper1]

Hey all first this site rocks! After two yrs of reading following threads my mind almost exploded when I learned of reasons why I lost quality smell etc and boom so simple but so important little thing. Srry Op I got caught up any way what I do is hang my four foot UVB vertical I'n corners and along the wall my bottom growth thx me hope this helps. And thank u SM/ TS/ and all of the contributors of this site one day very soon my shit will b grade A + instead of B+ my Wife says thank you also! Peace out