LEDs and potency
- Thread starter BobCajun
- Start date
Fastslappy
Well-Known Member
UVb is dangerous to your eyes
It will damage your cornea causes cataracts
Plz b aware & protection at all times
The effect is on going so little exposure adds up over time
It will damage your cornea causes cataracts
Plz b aware & protection at all times
The effect is on going so little exposure adds up over time
qballizhere
Well-Known Member
I personally use the 12% desert uvb bulbs http://www.lightyourreptiles.com/bulbs/arcadia/ I only use them the last 2 weeks a few hours a day to simulate high noon
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Astro Aquanaut
Active Member
Does anyone know how much UVB is optimal or how much is to much?
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testiclees
Well-Known Member
qballizhere
Well-Known Member
about 12 inches.. i believe that they will not be effective after 2 feet
Astro Aquanaut
Active Member
So, I was doing some simplified calculations and I was figuring for 115 watts of LED you should have around 4.6 - 5 watts of UVB to mimic high altitude. However the UVB lights seem to diminish quickly with distance, and am wondering what would be suitable for 18 inches...
Some bulbs am looking at
http://www.lighting.philips.com/main/prof/lamps/special-lamps/medical-lamps/medical-therapy-uvb-broad-band/uvb-broadband-tl/928011301201_EU/product
http://www.lighting.philips.com/main/prof/lamps/special-lamps/medical-lamps/medical-therapy-uvb-broad-band/uvb-broadband-tl/928034901229_EU/product
I am wondering if the 100 watt would perform better at a distance of 18 inches plus with a narrower band excluding UVA would suffice...
Basically, all my LED calculations are based for 18"... Any suggestions?
qballizhere
Well-Known Member
Not knowing the size area you have i would approach it like this you have a given area lets say 4x4 and you would like to go with a 18 inch from the canopy I would go with 2 3 foot bulbs one for a 2x4 area. you are only using uvb the last 2 weeks of flower.
Astro Aquanaut
Active Member
If I ran uvb @ 39 watts that would be 390 watts of uvb and 966~ watts of led for 5x5 that would be 28~% of my total wattage...
Think this will require some experimentation...
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qballizhere
Well-Known Member
Yes it will this is what I would try at first you can always add more uvb harder to remove it
have a look at the modification i did to give you an idea. You could always add uvb easy if you run screens add a few pieces of pvc pipe and you have a stand for them.
have a look at the modification i did to give you an idea. You could always add uvb easy if you run screens add a few pieces of pvc pipe and you have a stand for them.
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nevergoodenuf
Well-Known Member
This is where a reef dimmer? and a dimmable driver would be useful. Progressively get brighter until midday then start to dim to off.
Astro Aquanaut
Active Member
Think am going to build one panel 2 rows of LED separated by 2 uvb 54 watts then take PAR, and UV readings at different heights
I want a UV index between 5 and 8, and around 600-1k PPFD 18 inches below the center of the two rows...
ttystikk
Well-Known Member
I've been running CDM for awhile now and I'm changing over to COB LED. Do you have any experience with these?
Psyphish
Well-Known Member
Unfortunately no, I don't have any experience with proper COBs, but I'm considering buying some COB fixtures to use during the summer, probably going with todogrowled.es .
medicinehuman
Well-Known Member
I have been using 26w UVB lizard lights for some time now and they do work. When I went 12/12 and 3-26w UVB for the whole flower stage An Afghan Kush finished 7 days earlier than others that went without. The down side was A much smaller plant. I found that about 1/2 hour a day until the last two weeks then go 12/12 worked quite well, harvest was more normal and potency seemed better. Just my two cents
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Humanrob
Well-Known Member
I just want to make sure I'm understanding this -- are you saying that you had the UVB light go on 1/2 a day throughout flower until the last two weeks, and then it was on for the full 12 hours per day for the remaining time? Thanks for clarifying.
medicinehuman
Well-Known Member
Yes 1/2 hr a day until last 2 weeks then 12/12 , they don't seem to gain as much weight as without the UVB. It seems worth it.
Humanrob
Well-Known Member
@medicinehuman -- thanks for reply. Its interesting to see how different people go about it. I've read a couple of people say they run them for 4-6 hours a day for the last 3-4 weeks. It seems there is some debate about whether they have any impact before flowers really start to develop.
I've done just a little research so far, and there seems to be a pretty big variation on the output of the bulbs, so I'm guessing different techniques will work in part based on how strong and/or how many bulbs you are using. I'm not sure how accurate it is, but the manufacturers use a number to designate its 'microwatts' (according to one manufacturers description I read), like the the Zoo Med Reptisun is "10.0" and the Zilla Desert is "50".
I found some 18" 15w T8 bulbs and an inexpensive fixture for single bulbs. I'm thinking about getting two sets and using the aluminum L channels to make one long light out of them that will fit between the two rows of COBs I have in my main light. I guess from there I'll just have to try different amounts of time and see what works.
I've done just a little research so far, and there seems to be a pretty big variation on the output of the bulbs, so I'm guessing different techniques will work in part based on how strong and/or how many bulbs you are using. I'm not sure how accurate it is, but the manufacturers use a number to designate its 'microwatts' (according to one manufacturers description I read), like the the Zoo Med Reptisun is "10.0" and the Zilla Desert is "50".
I found some 18" 15w T8 bulbs and an inexpensive fixture for single bulbs. I'm thinking about getting two sets and using the aluminum L channels to make one long light out of them that will fit between the two rows of COBs I have in my main light. I guess from there I'll just have to try different amounts of time and see what works.
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medicinehuman
Well-Known Member
I put them about 12" from canopy, replace them regularly for best results( Reptisun 10.0 is what I use )