Airwalker16
Well-Known Member
I don't know what you mean
Help regarding choosing solution for adding UVA/UVB LED's to a DIY COB LED grow light.
- Thread starter Planet Tomato
- Start date
Airwalker16
Well-Known Member
Where's it say power out?
Airwalker16
Well-Known Member
This one is $300 but a 26V chip. Much bigger.
Humple
Well-Known Member
Just curious - what would you consider to be cost effective? What $/watt and what lifespan would it take to get you interested?
Edit: Silly me. Also, what kind of efficiency would you be looking for?
CobKits
Well-Known Member
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CobKits
Well-Known Member
im not sure what efficiency the tubes run at, but their output per $ is prob less than 10% of the LEDs
the only advantages the LEDs would have is efficiency or cost but doesnt seem its there yet
Airwalker16
Well-Known Member
You boards being labeled with actual UVB diodes on them now though. It used to be only UVA you'd ever see.
Humple
Well-Known Member
I suppose it's a question of whether or not the lifespan of the LEDs would make the price worth it, compared to a fluoro fixture that requires bulb replacements.
nfhiggs
Well-Known Member
That seems to be what the data sheet says. Get the UV tubes.
Randomblame
Well-Known Member
One would need a lot of these diodes to get comparable output like a UVB/A tube. A 4ft./54w Agromax tube at 1' delivers 440mW/cm² and her footprint is ~4x 2' or 0,72m². At 2' it's still 170mW/cm² and the footprint would be ~4x 4'.
UV light causes some changes within the plant, an immune reaction is triggered as well as some defense mechanisms.
Below is a UVB chart for natural UVB strength in summer. I would say these Agromax tubes fits very well. As mentioned earlier in the thread I would run it on a separate minute timer. It's very easy to damage you plant with 440μW. I've used ~125-150mW/cm² for the whole day with good success(39w Arcadia reptile bulp, 12% UVB, 4x 2' tent).
Not a single damage on the leafes but I found a few seeds and they are already deformed (one BlueDream hermied).
I'm pretty sure they could handle even more maybe 200 or up to 300μW without getting damaged.
But one should watch the girls well. Burnt leaf margins and tips are first symptoms that its too much. Twisted leafes and other deformings means it's much too much.
Plants should get used to UVB radiation as early as possible. I've used half the intensity already in veg.
At the beginning they got 2+2 hours UV light (with lights on and before lights off) and I increased it weekly until I ran it for 12/12 in bloom week 7.
Next time I will increase it faster and start already with 2x 3h and ~100-150mW a day, from bloom week 5 I will use up to 250mW the whole day. If damages occur I will reduce it untill the damages dissapear.
UV light causes some changes within the plant, an immune reaction is triggered as well as some defense mechanisms.
Below is a UVB chart for natural UVB strength in summer. I would say these Agromax tubes fits very well. As mentioned earlier in the thread I would run it on a separate minute timer. It's very easy to damage you plant with 440μW. I've used ~125-150mW/cm² for the whole day with good success(39w Arcadia reptile bulp, 12% UVB, 4x 2' tent).
Not a single damage on the leafes but I found a few seeds and they are already deformed (one BlueDream hermied).
I'm pretty sure they could handle even more maybe 200 or up to 300μW without getting damaged.
But one should watch the girls well. Burnt leaf margins and tips are first symptoms that its too much. Twisted leafes and other deformings means it's much too much.
Plants should get used to UVB radiation as early as possible. I've used half the intensity already in veg.
At the beginning they got 2+2 hours UV light (with lights on and before lights off) and I increased it weekly until I ran it for 12/12 in bloom week 7.
Next time I will increase it faster and start already with 2x 3h and ~100-150mW a day, from bloom week 5 I will use up to 250mW the whole day. If damages occur I will reduce it untill the damages dissapear.
Randomblame
Well-Known Member
Yea, sun glasses, long-sleeved clothings and gloves are a must or you have to turn it off each time you enter the room!
These Agromax tubes still deliver measurable UV light at +48" distance. With reptile bulbs you can still measure UV light at 28-32"(10-14% bulbs).
I believe the UV-A in reptile bulb is a plus.
Airwalker16
Well-Known Member
The Pure UV bulb from Agromax is 75% UVB and 25% UVA. Rather than both UVB and UVA being around 10-15% of the whole Reptile Bulbs output.
Randomblame
Well-Known Member
Yea, it is! But usually these tubes all produce both typs of UV radiation + some visible light. The UVA output is almost stable over time but the UVB output decrease by ~30-35% every 1000h of usage. The good thing with the Agromax bulbs is even after 1000h of usage they make more usable UVB like a brand new reptile bulp(max. 14% UVB, Arcadia D3dragon).
1000-2000h old Agromax tubes could be used in the veg area where less UVB strength is needed.
CobKits
Well-Known Member
Randomblame
Well-Known Member
Ah, thanks.
I've tried another keyboard app and it did not have a "μ" letter.
Had to install the greek language package, lol! Now it works again but its too late to change it anyway..
nachooo
Well-Known Member
Last crop , I noticed some seeds with exactly this kind of deformation… The mother was a sativa, normally it produces nice elongated médium size sedes...but this time I saw that some sedes were broader...like indica ones and some of them have this deformation...exactly the same.. I did not know the reason..and was tempted to post about it… Well i know why now… And yes I used 10 hours a day a compact reptil uvb… Little but the high uvb producer I found in Spain about 15%. So I see I was using too much uvb.. mostly cause I do not move the uvb lamp to other places in the tent like in other crops..lazy man I was….
Anyway… I should have some seeds like this and others specially bigger than usual..Also they were darker in color... Should I expect something special If I plant them?
My indica strain developed little and darker seeds than usual...
