single cob or multiple 3watt leds

L

littlegrow

Active member

• Aug 6, 2014

• #1

Hey guys so i have been scratching my head for most of the day is it best to go with a single 2700k cob or is it better buying 3 watt led's with the right nm ranging from 400 - 700nm ?

i want to build my own but i only want to do a small led grow i don't wanna use a 100 watt cob yet.

 

D

Dr.Tone

Member

• Aug 12, 2014

• #2

Multi point lighting beats single point hands down. Go with the 3 watters with 90 degree optics, youll have penatration and coverage. Most cob sytle emiters are very unefficient in terms lumens per watts. When looking for a fixture id more then likley go with 2 smaller unit then 1 big one. Id say like 250w actual draw fixture per plant would get you an awsome yield. 4 of those in a 5x5 area with 4 plants and youd be rockin.

 

3dDream

Matter that Appreciates Matter

Veteran

• Aug 12, 2014

• #3

a cxa3070 has 132 leds and shoots at 115 degrees with no lens. Keep the xmass lights on the tree.

I find the longevity and the lack of IR heat (vs hps) to be the reasons I like leds.


What about a dimmable cob?

 

L

littlegrow

Active member

• Aug 22, 2014

• #4

they both sound like good ideas im gonna go with the 3watt leds, i have been trying to understand the math and so far i think i am understanding it

so tommrow im buying 10 3 watt red 660nm
10 3 watt Royal Blue 450nm ~ 455nm
can the lenses be changed on the LEDs ?

so if i buy leds which have 120 Degrees lenses can i change them for 90 degrees

 

PetFlora

Well-known member

ICMag Donor

Veteran

• Aug 22, 2014

• #5

littlegrow said:

they both sound like good ideas im gonna go with the 3watt leds, i have been trying to understand the math and so far i think i am understanding it

so tommrow im buying 10 3 watt red 660nm
10 3 watt Royal Blue 450nm ~ 455nm
can the lenses be changed on the LEDs ?

so if i buy leds which have 120 Degrees lenses can i change them for 90 degrees

Click to expand...

660s only provide ~ 5% PPFD, whereas the < 650 range is 95%. A 3000K provides pretty much all you want

A few Royal blues are a good idea, but do nothing for the much needed 500-600 nm range. Again the 3000K does

So, ~ 15% RBs + ~ 75% @ 3000K + ~ 10% @ 650s for the win