420Blunt's
Well-Known Member
awesome thread!
10.0 Uvb Light
- Thread starter weedyoo
- Start date
I'd almost certainly say it's heat.
When you use your thermometer to measure the temperature, you're measuring the air temperature, which is set by convection and warming of the air.
That kind of burning is more to do with radiation. The leaf is green and designed to soak up light, but if you pound the shit out of it, the pigments break down. It's a kind of bleaching effect. All plants use the same kind of photosynthetic reactions, and there's actually a mechanism by which they can shutdown the photosynthetic pathways if they start getting bombed out with too much light.
You wouldn't be able to measure that kind of heat very easily with a thermometer in the air. It's one that's better measured by putting your hand at canopy height for a while. If it starts getting quite a lot warming than it was, the light is too close. Keep in mind that the leaves are green, your hand is white or brown and the lamp is designed to output power in the spectra the leaf absorbs - so whatever you feel the plant is getting it worse. The air might be reasonably cool, but the surface of the leaves could be a lot hotter.
When did it appear and how quickly? Was it when you started using the UV? Had you just moved your HPS, the pots or had they just come through the mesh?
I'm almost certain that's radiation damage over nutrients, pH or general room temperature - I've seen it on mine and know for sure that it's from when the lamp got too close and the fan went off.
82f (27c) is a little high, but it's not brutally high. My first over the net, can't see exactly what's going on guess is that you've got decent cooling on the lamps / room but the lamps are too close.
Haven't tried UV yet, but I know it's used a lot in treating air supplies. Hospitals can buy special air filters that blast the air with UV to kill bacteria and I know it can also break down molecules directly or by supercharging something nearby into doing it (I think moisture would work as a superchargable thing - not sure atm).
I think we need to be careful of not cooking our plants with one really bright, really close UV lamp in this experiment. The reason the UV is working is because it's chemically changing the resin. If it gets toasted by 10x more UV than the sun puts out, that's probably not going to help it out. It'd be like feeding the plant ten times more nutrient than you find in soil - it'd die rather than grow really quickly.
Go for lots of low wattages, a light mover or move the plants I'm thinking.
Remember that light spreads out quicker than you think. Once it's twice as close, it's a lot more than twice as intense.
Found this article looking at lights for reptiles, the lights used in insect zappers seem to have high UVB as well, not sure how to tell between the Sylvania 24" 20w and 18w Blue, though there is a big difference in output.
http://www.mark.org.au/pages/uv_comparison.htm
Outputs are also compared to sunlight
http://www.mark.org.au/pages/uv_comparison.htm
Outputs are also compared to sunlight
Sunbeds as well
Landragon
Well-Known Member
UV lamps produce ozone. A good reason to not run them a full twelve I'm thinking.
Looks like you can get high output UVB lamps for reptiles, the all in one designs make extra heat though
http://www.reptileuv.com/megaray-sb-100-watt-self-ballasted-flood-uvb-lamp.php
These seem to be 4-5 times the output of fluorescents, and are not too expensive.
Fluoro = 35uw/cm2 at 12"
Rep bulb = 150 - 200uw/cm2 at 12", or better with 160 / 275 bulbs, similar output at 18-24"
http://www.reptileuv.com/megaray-sb-100-watt-self-ballasted-flood-uvb-lamp.php
These seem to be 4-5 times the output of fluorescents, and are not too expensive.
Fluoro = 35uw/cm2 at 12"
Rep bulb = 150 - 200uw/cm2 at 12", or better with 160 / 275 bulbs, similar output at 18-24"
Had another look at the site, I thought light output was 30" diameter at 20" distance, but it is 30" circumference at 20", which is more like a torch. I guess unless you were using one bulb per plant the fluoros are looking better. Sun bed lamps seem to be more UVA, so reptile or insect killer bulbs still have the best UVB output.
Moldy
Well-Known Member
I use a couple of 10.0 Reptisun 24" on either side of my small 400W 4 X 3.5 garden. I keep mine on about 4 hours a day during flowering. I think it helps but in order to really give UVB a good test it needs to be more intense like some mentioned earlier saying the tanning bed lights were the best. There is another thread on this that went into it pretty deep but I never saw any conclusive evidence either way. Some growers say flowering with HID will give some UVB but I didn't think UVB will go/pass through glass? The glass on the Reptisuns are made from quartz I believe. Either way it's an interesting and highly augued subject.
Yep, UV is very picky about what it will and won't go through - so it's best not to put anything in front of it. Specialized scientific UV lamps that costs hundred or thousands of dollars still have serious limits set on them just by the glass they're made out of.
There's a band between UV and X-ray where almost everything solid becomes opaque to the radiation. It starts in UVA and get's worse towards UVC, then gets betters as it goes back to X-Ray. Quartz is one of the more transparent things.
If you haven't tried smoking it yet, it might be that the biggest change is there rather than in the trichome coverage / size.
There's a band between UV and X-ray where almost everything solid becomes opaque to the radiation. It starts in UVA and get's worse towards UVC, then gets betters as it goes back to X-Ray. Quartz is one of the more transparent things.
If you haven't tried smoking it yet, it might be that the biggest change is there rather than in the trichome coverage / size.
AnonGrower420
Well-Known Member
thats whati hear. mines only a 5.0 UVB ReptiSun 14W for my 2 girls but it seems to get the job done. its been in there for a least a week no and i wouldnt say i noticed a difference because my plant was really frosty before but its not making naything worse so it stays in for. i started another UV B thread in another section before i stumbled onto to this one. i was going to do a control test next grow but would be better if someone else did one
Does anyone know the stability or lifespan of THC in the plant? The guy in the video says about using UVB even in veg, but I'm wondering if you could just use it for the last two weeks and get the same effect.
Sun Pulse recommend a blue 10K bulb for the last week only of flower http://www.sunpulselamps.com/doccuments/postcard_4x6.pdf
Sun Pulse recommend a blue 10K bulb for the last week only of flower http://www.sunpulselamps.com/doccuments/postcard_4x6.pdf
murtymaker
Well-Known Member
Well I just read the whole thread and am pretty confused on what to get and when to use it? I have a 4x4 aero set-up with 36-sites under a 1000wHPS and an 8 strip T-5 fluros. So if I have 16sqf, I should get TWO 10.0 UVB lights? ... I think someone said that they are 20w? And when is the best to run them? For about 6 hours out of the 12? Thanks
BloodShot420
Well-Known Member
basically - the 18" fluoro tubes are 15watt and the 24" tubes are 20watt...
with the size you have, i would say you should get two of the 24" tubes, at 20 watt...
BUT - that is nowhere near close to outdoor uvb, so you could put in as many as you can, they should be adjustable independently of your other lights, so you can back them off if you see plant burns... and you probably want to run them 6-10 hrs a day during flower, and they say its good to introduce it to them in veg - so maybe 2 hrs a day during veg.
there's no right answer (yet) - but uvb makes it better, according to anyone who's tried it or done any testing.
with the size you have, i would say you should get two of the 24" tubes, at 20 watt...
BUT - that is nowhere near close to outdoor uvb, so you could put in as many as you can, they should be adjustable independently of your other lights, so you can back them off if you see plant burns... and you probably want to run them 6-10 hrs a day during flower, and they say its good to introduce it to them in veg - so maybe 2 hrs a day during veg.
there's no right answer (yet) - but uvb makes it better, according to anyone who's tried it or done any testing.
murtymaker it will be tricky to get good coverage with that size room. Bulbs need to be about 12" from the plants to get good uv levels. Try one of thesehttp://www.foxelectricsupply.com/content/products/ProductDetail.asp?qsCatID=25252&qsProductNo=F40/BL in a 4ft holder along one wall near the plant tops. If you notice a difference you can add more lights to the other walls.
weedyoo
Well-Known Member
this is not the light i am talking about
are some people confusing uv with uvb their is a big diffrence
now i have one light that i move around the room 10.0 uvb so all my plants only get a few hours each its like any thing you will learn http://www.petdiscounters.com/Repti-Glo-100-UVB-Compact-Fluorescent-Bulb-26-Watt-p8334.htmlRepti Glo 10.0 UVB Compact Fluorescent Bulb - 26 Watt
Ideal for all desert dwelling reptiles. The Exo Terra Repti Glo 10.0 has a very high UVB output similar to that associated with desert environments. Desert locations receive more direct sunlight than any other because of fewer clouds, less air humidity and no plants or trees to provide shade. Therefore desert reptiles are more exposed to UV radiation than any other type of reptile.
Ultra High UVB output is effective up to 50 cm (20"). Provides necessary UVB rays for optimal calcium metabolism. This bulb can also be used on screened terrariums or terrariums with dense screen covers to ensure UVB penetration. Dense screens can filter out up to 50% of the UVB rays.
The advantage of the Exo Terra Repti Glo Compact Fluorescent bulb is its size and the fact that it is self-ballasted. A regular screw fitting is sufficient to operate these bulbs. The spiral shape of the bulb enables vertical or horizontal mounting without compromising performance.
It is recommended to combine a high UVB output (Repti Glo 5.0 and 10.0) with a very high visual light output (Repti Glo 2.0) for optimal results. Fluorescent bulbs do not provide sufficient heat. A separate heat source is required in addition.
Our Price: $11.95
weedyoo
Well-Known Member
well i run the this light when i run hps but i move this light to 4 diffrent hooks in the 12.
as i do believe if you leave the 10.0 on the same plants or plant you will see the green pigment start to change to yellow
GrowBabyGrow41
Active Member
Great Thread!!! I got a 10.0 26w cfl on ebay. I'm in on this. I saw the Video on youtube. came straight here and as always you guys was on it.. keep up the info.