UVB usage recommendations


I was able to pick up a Cirrus LED - Reflex UVB Bar LED Grow Light because the company changed and decided it no longer was going to venture into the grow / horticultural field and just focus on other projects.

I have a small 5 x 5 grow set up and want to ask:
1.) For how long do the UVB lights stay on? total time in hr or min.
2.) When should the light be in use during the 12 hr light cycle.

The reason I ask is due to conflicting info I’ve come across in my research. What I’ve read is recommended time on:
45 min per day
2hr per day continuous
2hr per day broken up into four 30 min sessions
Up to 3 hours

I’m several weeks out from needing them since I plan to use them in the latter stages of grow / bloom before harvest, unless your comments change my mind

Thanks in advance

What are the light specs?

Hopefully this helps. I haven’t had the chance to put my UVB to work yet but this is what I found when researching on getting one. UVB 2-3 Hrs a day and UVA 12ON/12OFF

Here is where I pulled info

If you check out the Migro channel on YouTube you’ll find Shane has posted extensive information on light schedules and distance from canopy etc - to summarise I’ve cut this from his website where he sells his own 18w UVB fixtures:

‘Recommended use: 2 hours mid-light cycle for the last 3 weeks of flowering at hang height of 2 feet’.

He also suggests that you monitor your plant for the first few hours and make adjustments as necessary as different strains may not tolerate 2 hours straight away (reduce time to 90 mins etc then build gradually to 2 hours over period of days).

Sorry I didn’t find your thread sooner…

Check out this thread… It is why I didn’t buy one.

So far I use T5 fluorescent uvb bulbs but still looking into led… So far without luck.

I like the he has charts to show the test results… But very expensive… I wonder the difference between his and the agromax ubv t5 bulbs?

Thanks !

My timers are cheap and can only so I’m planning to run the UVB for 30 min, 2x for a total of 1Hr for each 12 light cycle.

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Since cirrus no longer produces them I got them at clearance price $25.00, found them on FB Marketplace, but that was a long time ago and they have since probably sold out.

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@Russell_Leaves My point was their specs listed it at 430nm…that is not uvb… In fact it is not even uva.

Sorry. I had seen them on ebay a while back and almost bought them until I asked the forum about them.

It’s hard to say if there is a difference but Shane has gotten a reputation for excellence in the lighting industry. He’s an engineer and spends all his time researching, designing and developing his his own light - you just know that what you’re getting is the best out there. Yep, he’s an extra couple of Euros but it’s unlikely you’ll read a bad word about his products.

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