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How long does everybody run UVB?

I’ve just bought one, but have heard many different ways to run them. Can’t afford to burn
Up a crop. Any help appreciated.

I run the agromax pure uv 4 foot have it on a timer for 12 min ever hour ex. On at 1 off at 112 on at 212 off and 224 on at 324 off at 336 etc. And have it at a hanging height of about 20

My quantum boards have that built in. When they came out i got 4 boards at 170watts each they can bleach plants very easily. But then i added 4x of the hlg elite v2 engines. So my answer is i never stop using mine from seedling to harvest. The second my seedlings see light they get light that is 80% 5500°K, 10% 460nm blue, and 10% 380 nm UV. It is specifically designed to work with your existing 4 ft T5 fluorescent fixture. For vegging and it works flawlessly! I grow with just one of them. Then i do medium veg with 4x bulbs. Then i move to quantum boards @3500k then to full spec QBs or my other tent that had 4 QB’s there 3500k and far red with 3500k mix.
These are the bulbs i use.


Thanks for the input. BTW my lite is a
CLW 28 watt. I bought it being told by
Growershouse that it would plug into my
Controller Not! So now I have to come up
W/another timer.

I would call and complain. They will fix it. They messed up my stuff/order and took care of it.

380 nm uv doesn’t do anything as its uva what you want is UVB because using an analogue the sun emits uvb and gives us a sun burn and our skin rebuilds when u use uva nothing happens think of a black light from walmart. Using a uvb (NO LED HAS UVB, IFTHEY SAY THE DO THEY ARE LYING) the uvbgives the plants sun burn and they regrow their skin but their skin is TRICOMBS go to YouTube and look up MIGRO he has done extensive research on the uvb subject and bot only shows that the is NO UVB LEDS but also shows what the best uvb lights are (AGROMAX PURE UV) and what uvb actually does to plants. Another person to watch on YouTube is Dr.Bruce Bugbee of APOGEE INSTURMANTS these 2 people have more knowledge of lighting then anyone I have ever know.


Thanks for the input @preybird1&@xgx13xgx,but I was wondering if anyone was running a CLW 28 watt uvb. The only timer I have atm has 30min intervals. So I ran it 30min at 24inches & it burned all the fan leaves up! No worries though, I 'm trying to get them to finish.

Go buy a digital timer. Idk about the uvb u r running I have the agro max pure uv 4 foot fluorescent bulb at about 24 to 36 inches cause at 18 my last run burned the fan leaves but at 24 to 36 and 8 min per hour it works great my buds are so frosty cause of the uvb I have grown both of the strains before and everything is the same except for the uvb and it looks like snow


I will get one for sure, Cali. Light Works recommends 3 ft. above canopy. I just can’t get it that high on this run,( ran out of room, ceiling).

MIGRO did a test of the uvb lights including a “led uvb” which was bs n e way the agromax pure uv was the best output of the uvb and I swear by it I’ll get some snowy pics later to show the tricomb growth it is amazing so damn sticky to

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If my light was any stronger I would need a bigger room! @xgx13xgx working on posting a picture. So far, got 1 on my post about finishing. Working on more… could use some input on that.

I want to do exactly this sir.

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Uvb is not bright at all I have my led rig running on 570 watts and 18 to 20 inches off canopy, I have the uvb at my roof now rather then about 3 feet because this morning more of the leaves were burnt and I know it’s from the uvb but to be sure I’m going to lower the led out put to about 500 watts. The uvb again isnt bright but it is rather the spectrum that it is putting out that burns em if left in that spectrum for to long or to close

Its not the best pic of the uvb but shows how high up it is lol and the frosty buds omg

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What brand is your light? @xgx13xgx
Ill be testing my uv boosters on this run actually.

It’s the one shane from MIGRO recommended which is the AGROMAX PURE UV I have the 4 ft but they have a 2 foot
Be warned this thing is strong it burned my last run hanging at 18 to 24 inches (resting on top of my led rig) and set at 12 min per hour
This run I had it at 24 inches or so and on 8 min per hour and they started to brown over the last 2 days so it’s now at my roof about 36 inches or so still on for 8 min a hour I’ll update with this in a few days

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Oh i will be doing testing 1st before i run it. But appreciate the heads upa :+1:

Update on the UVBi made a huge mistake in understanding shane from MIGRO
The light he tested was the agromax pure uv 2 FOOT not the 4 FOOT THAT I USE in the video he said that the 3 watts of uvbthe 2 foot puts out is enough for a 1 sq meter grow area which is 3x3 ft I’ve been using the 4 foot tube for a 4x4 space for 8 min per hour 8 hours a day for a total of 64 min well my leaves have started burning and light bleaching so I raised my lights lowered my watts to 500 over 575 and the uvb I raised to the ceiling and moved to 4 min per hour for 8 hours totaling 32 min which is more then adequate being that a 2 foot tube is for 3x3 at 1 hour per day so I figure a 4 foot tube is made for a 6x6 but being as I have a 4x4 i feel thata4 foot tube in a 4x4 tent that32 min of 6 watts of uvb is good I’ll keep u all updated

The CLW people recommends a minimum 3
6inches, & says it 's good for 4×4 . Mine is 2ft.
@xgx13xgx @cjones @ @preybird1 I really
Appreciate your input. My next flower cycle I will
Mount it on the ceiling!

Wow thats a ton of output.