LED questions for newbie.

[mmmnq]

Goodday everyone

I got a 3x3 grow tent from Gorilla and my next purchase is a grow light. I've been researching and so far I got to the conclusion that I will just buy the CLW SolarSystem 550 because it gots bells and whistles like automation stuffs.

But upon reading the forums, most of you recommend the COB panels. Now I'm a beginner and I don't really know the differences from COB panels to the SolarSystem 550 that I was about to buy. From what I have gathered, COB panels are white. How can white be better for growing? What are the advantages for COB panels over the standard LED panels?

I've also read that I need around 450 watts for my grow space. I only want to buy one LED so is 600 watts overkill for my plants?

Thanks!!

 

[TheEEngineer]

So I currently flower over a 1m^2 area using 450 watts of cxb3590.
While the light is white it is important to remember that 'white' light is comprised of many different wavelengths which is similar to how an HID creates light. Typically prior to cobs LEDs tried to recreate the spectrum used in flowering by mixing different wavelength diodes in an array, giving you the reds and purples.
This is an example of the spectrum a cob creates with different color temperature cobs and cri (color rendering index)

COBs are typically regarded as the superior albeit more expensive route to go with LEDs, I will say that I am sold on their advantage over a typical led panel having previously owned one. It is quite a bit more expensive however figuring that each cob with a holder and lens will cost roughly $40-45 plus a driver for the cobs (you may need multiple depending upon how many cobs you are running) then some sort of heatsink, I personally went with passive pin heatsinks.
I hope this helps, if you have further questions feel free to ask!

 

[mmmnq]

Hi TheEEngineer, awesome set up!

You said that COBs are superiour LEDs, can you tell me the advantages of COBs light over typical LED panels?

Also there's a lot of Color temps for COBs. Do I need to buy different color temps for my grow or is it better to combine two color temps?

I read that 3500k is good for flowering and 4000k is good for vegging. How can 4000k affect my vegging and 3500k affect my flowering? Will it have a huge final effect?

 

[TheEEngineer]

So cobs produce the type of wavelength I posted in the picture on my previous post whereas led diodes produce one main wavelength with some power fringing on the edges.

I personally am using the cxb 3500k CD bin chips, I have heard about people using a 4000k or two in the entire array to even out the spectrum but I have not done that.

Another advantage to cobs, you can create a near even canopy of light by spacing out the cobs like I have done.

 

[mmmnq]

I plan to buy COB @ Timbergrowlights now. But I'm not so sure on how many should I buy. I've read that 65 per sq foot is good for growing. So does that mean that I need something like 585 watts of COB in my 3x3 grow tent? Will 12 COB fit inside the grow tent? Will the heat become unmanagable?

 

[TheEEngineer]

For my 3x3 grow space I went with 450w of light, I will take and post a picture here later today of them. Doing some quick calculations at the worst possibly efficiency I got ~1250 ppfd, I do not run them at 100% either. As for my situation, heat is a non issue.

 

[Dr Fish]

This 12 oz plant would have filled a 3'x 3' tent... watt for watt my SS-315 watt mh lights will cover as many sq. feet, and grow as well as any cob of equal wattage, at almost half the cost... Not knocking the performance of cobs, just their price...

Blackberry

 

[TheEEngineer]

Now you could build a 7 cob setup with cxb3590 for ~415, it would be about 350 watts at roughly a 56% efficient light (could be slightly less depending on ambient temperature).

COBs have gone down in price considerably however with that said I am looking at getting a lec 315 for my 2nd tent just to see what they can do.

Also just took these pictures at day 26 of flowering under the 450w of cxb3590.