Vero 2 or Cree CXB?

Hello,

I will be buying some new chips soon.

I will be running 4 x 700mA - I take it at this drive current the preferred cob is the cree?
Would I get a better spectrum mix from 2 x vero and 2 x cree?
is the opinion still that 4 @ 3000K is the best option?
or maybe 3 @ 3000 and 1 @ 4000?

Any advice appreciated

Cab is small (900t x 450 x 450)

I Like Vero but 700ma is defiantly Cree territory especially if you get the better bin

If you're looking at 700mA I would stick with CXA/CXB.

CCT is a matter of preference at this point. To make a big generalization:3000k=flower (still works for veg) 4000k=veg/flower.

Some like to run 3500k so they don't have to worry about light spread/mixing.

The vero series is practically plug and play since the cob holders are integrated. Cree chips require a cob holder that is sold separately. The CXB series is appreciably more efficient though.

No point in mixing. Get one color and stick with it.

thanks bicit, is there really no sense in mixing a 4k in? I looked at the spectrum graph on the datasheet and it shows the 4k giving a big peak in the blue end?
Are you saying that the 3k will provide enough blue anyway?

4000k will veg slightly better than 3000k and vise versa for flowering.

There's no sense if you want the same spectrum over all your plants.

UKpeanuts said:

thanks bicit, is there really no sense in mixing a 4k in? I looked at the spectrum graph on the datasheet and it shows the 4k giving a big peak in the blue end?
Are you saying that the 3k will provide enough blue anyway?

Click to expand...

define 'enough'

3000k, 3500k, and 4000k, all grow beautiful flowers full cycle, period. The differences are going to be very nuanced. so unless you're running the same clone in super controlled conditions, you probably won't notice the difference. Even the 2700k emitters work.

FWIW I use 4000k, probably going to move to 3500k for higher photon density.

bicit said:

define 'enough'

3000k, 3500k, and 4000k, all grow beautiful flowers full cycle, period. The differences are going to be very nuanced. so unless you're running the same clone in super controlled conditions, you probably won't notice the difference. Even the 2700k emitters work.

FWIW I use 4000k, probably going to move to 3500k for higher photon density.

Click to expand...

Does 3500k have higher photon density ?
Will photon density be higher if cob has higher lumen/watt or its not related

Thanks all,
I will see whats available,
I like the idea of mixed nuts
2 x 3k
1 x 3.5k
1 x 4k

ty ty

UKpeanuts said:

Thanks all,
I will see whats available,
I like the idea of mixed nuts
2 x 3k
1 x 3.5k
1 x 4k

ty ty

Click to expand...

suggest you stick with 3K and add a few royal blue stars instead of trying to do the Chinese menu thing with white cobs of different temp. by mixing white cobs your adding more green light than you probably want. luxeon has some nice 12 watt royal blues. you can get them at steves led (http://shop.stevesleds.com/main.sc). The royal blues are more efficient than any of the white cobs afaik.

robincnn said:

Does 3500k have higher photon density ?
Will photon density be higher if cob has higher lumen/watt or its not related

Click to expand...

Has more to do with where the energy is being distributed. Blue photons carry more energy, so there are less of them from a given power displacement.

photons ? despite being able to model light as particulate its not particulate, its a wave.

PurpleBuz said:

photons ? despite being able to model light as particulate its not particulate, its a wave.

Click to expand...

It's both

Looking again to the datasheet there is quite a large difference in lumen output between a top bin 4k and a top bin 3k.
Are we saying that the CCT trumps lumen output, or vice versa?

thanks, UKP

UKpeanuts said:

Looking again to the datasheet there is quite a large difference in lumen output between a top bin 4k and a top bin 3k.
Are we saying that the CCT trumps lumen output, or vice versa?

thanks, UKP

Click to expand...

Neither, honestly. No one has conducted any rigorous scientific studies of all the different CCT and cri combinations available. It's impossible at this point to say what trumps what.

CCT, CRI, lumen, are metrics for human vision and essentially useless values for plants. Photon density and spectral distriubution are the important metrics that we (at this time) derive from the aforementioned human units.

This isn't specific to LED either. There is a bit of debate when it comes to the 930 and 942 CMH bulbs(3100k vs 4200k)

Moral of the story is that the differences are so slight that there is no conclusive winner, which means that you can't go wrong with any choice.

What would you buy? 4 cobs, 3k or 3.5k?
I'll prob go for 2 of each... Maybe I'll just toss a coin heh.

thanks dude,

UKpeanuts said:

What would you buy? 4 cobs, 3k or 3.5k?
I'll prob go for 2 of each... Maybe I'll just toss a coin heh.

thanks dude,

Click to expand...

I'm probably going to go 3500k until there is an agro spec. Seems close enough to ideal.

3.5 it is.
cheers dude.

For any given color temp there is also a tint.

Some are skewed toward green and some toward red. Assuming lumens/bins were equal, red tint would mean more photons emitted and slightly more photosynthetically efficient spectrum on top of that.

So if you had a 4000K CD bin that was skewed toward green and a 3000K CB bin skewed toward red, the CB may actually grow equal or more bud than the CD. It would depend what the tint was and where between the min and max range the lumen output fell. Without spectroradiometer readings for each COB we really dont know for certain. Luckily we do know that we will get awesome results either way