Quantum Boards: Are they worth it? Why or why not?

Danielson999

Well-Known Member
Well, you can get cobs from 1750K up to 8000K and probably higher. With QB's you're stuck at 2700K to 5000K I believe. So there's that.
 

Roger A. Shrubber

Well-Known Member
i veg under a mix of 3500k and 5000k, and grow bushy, healthy plants, i'm not sure what you'd want an 8000k light for.
seems like it would grow spindly beanpoles that would only get worse if you flowered them under anything a lot lower/
 

Danielson999

Well-Known Member
i veg under a mix of 3500k and 5000k, and grow bushy, healthy plants, i'm not sure what you'd want an 8000k light for.
seems like it would grow spindly beanpoles that would only get worse if you flowered them under anything a lot lower/
Sure, if you chose to only use 8000K. But realistically you can mix those 8000K cobs with any other spectrums also. I suppose this is another benefit of cobs. Not saying it would always be better but you can mix up any combination of spectrums you like. Some people like that option.
 

Rider509

Well-Known Member
I'm growing under a mix of 3500K 80CRI 3590s and Samsung FB24Bs. I can't say one is better than the other in terms of spectrum, but what I can state definitively is that the 3590s throw much more pronounced shadows on the leaves under the canopy at identical PPFD numbers. For reference, I'm running the 3590s at one per square foot without reflectors and both systems are running at about 14" from the canopy.

edit: You're right, Humple, I meant Lennox. :)
 

pop22

Well-Known Member
No, they have less heat radiated from the front than cobs, try actually measuring it with a infrared thermometer. With the diodes spread out heat is dissipated from the rear much easier than heat from a cob with its concentrated diodes, the tighter you pack them, the harder it is to get rid of the heat.

I went back to cobs. The heat with a cooltube diy runs cooler. The surface mount diodes seem to have more heat in the front which was harder to get rid of. The "legs" get warm. I thought of a way to put a cover over the QB boards (4) to move air in the cooltube stream but then losses occur. Plus cleaning a clear cover. ymmv
 

dandyrandy

Well-Known Member
No, they have less heat radiated from the front than cobs, try actually measuring it with a infrared thermometer. With the diodes spread out heat is dissipated from the rear much easier than heat from a cob with its concentrated diodes, the tighter you pack them, the harder it is to get rid of the heat.
The heat tends to radiate from the "legs" on the sip. Where the thermal junction is behind the les surface on cobs which allows me to remove the heat on the cooltube design I use. My 4 panel unit got the small room hotter than 8 cobs at the same wattage. I ran this test for 3 months. 3 to 4 degrees hotter on the panels. I have 4 I'm not using. I use 16 3590's. Sorry
 
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