Melissa Corner: LED Cree COBs


I think all the hype right now in grow light technology is LED lights.   Their energy efficient, they produce less radiant heat then HPS which spectrum is more toward the RED and IR wavelength.

Optic 1 COB 100W Grow led 3500k

Optic 1 COB 100W Grow led 3500k

The problem with LEDs is you almost have to have an engineering degree to figure out what all the specifications mean?

Actual Power Draw.  That’s easy the actual power drawn from the wall.  Par efficacy: 2.1 umol/j.  What does that mean?  Grams per watt?

Right now, I think it’s difficult to see what the specs mean?  Are they real?  What’s the real yield possible?  

So I asked the engineers at growindustriesinc who install high end commercial led like Fluence SpyderX and California light works etc;    Whats the real deal with LEDs?  The design state of grow facilities surely they know what the real story is?

According to them there good for good growers who know how to use them.   Long story short their not for newbie growers.  They seen and fixed a lot bad grows who incorrectly use LED technology.  They are about 30% efficient.  The technology is evolving fast.  The yield king at their sites is still HPS 1000 DE, some of their facilities are pulling 3.5 or more lbs a light.


What LED to use for the home growers?

Personally,  I like the Cree COBs.   COB = chip on board.  This basically means Cree packed a bunch of led in a tight area.

Simple clean design

Simple clean design

What’s so great about them their simple, no ballast, one COB can do 50W to 100W.

The one I personally like for flower is

Optic LED Optic 1 XL COB Grow Light (100W / 3500K)


Its got a great flower spectrum.  It comes with a ratchet hangar.  It takes about 30 seconds to setup.

The down side it coves about a 2x2 area.    I typically start them high like 24’ to 30’ once I flip one flower.  and then every 2 days I lower it.    This way you gradually introduce the plant and you don’t shock them to the intense beam.   Think Laser.   Led like to shine in one directions.    They don’t have reflectors so they have small area of coverage. 

If you have them too close to start you wont get the stretch in week 1 to week3.  You might also stunt your plant.   I always go high and lighter on nutrients at start of week 1 flower.  A par meter really helps.  But with these cree cobs  a cheap lux meter works decently.  Just to get a feel of intensity.  Lux meters wont work with the red to violet color LEDs.


Why do I like them for flower,  keeps my temps lower.   Also I like to have a perpetual grow.  Where I move a new plant to flower in 2 weeks.   So I typically have 2- 3 cobs in my tents at various heights depending on what week the plant is in flowering.


What you need to be careful, is since they emit little IR radation.  You wont feel heat at the canopy.  Which can cause you to light burn your plant because of lack heat on the canopy.  Reality if you get to close your pounding that flower with concentrated beam of light if your not careful.

Long story short, I like these Optic 1 Cobs, great 5 year warranty.  Simple passive heatsink design.  Easy to setup. Perfect for small MMJ grow tents.  Lower canopy temps make it a great light for DWC or recirc hydro setups.

You can find out more about the specs and order it with this link below: