Yeah supra,s is the man when it comes to led like you sed far to much info for a novice led I'll have a look at the three you sed anyway good luck with your build and I'll let you know how I get on in the near future keep growing P

I'm completely new to all of this so I have a lot of questions. Seriously, pretty much everything is new. I read through most of this thread but still don't quite get all of it. I guess I should start with what I'm trying to do. My goal is to find out if it will be worth it to build one of these rather than buy a LED grow light online. Budget is an important factor. I'm looking to spend $150 to $200 max. I have easy access to cheap heat sinks and fans so all I would need is the COBs/wiring/driver.

so..here goes

On LEDs grow lights I have been researching they list the nm. With these it's k. What exactly does K stand for and how does it effect the LED? Are COBs all full spectrum?

What exactly are bins and what makes them good or bad?

Why is it important for the heat sink to be perfectly flat to the point of sanding it?

OK so now for what I'm going for. I'm looking to have a approx 4x4 grow area and fit as many plants as I can. From what I read here I'm thinking possibly 4 CXA 3070's? Could I use less and run at a higher voltage?

I see people saying you can run COBs and different watts. Do the amps you run to it decide that? I'm completely new to everything I'm not sure how it all ties together (volts, amps, watts). I know the driver would have amps and volts but I guess I don't get if you have a driver pushing x amount of volts how you could vary how much each one gets? I hope this makes sense I'm sure it's frustrating to read for those of you that know your shit.

If I were to go this route what would you suggest for my setup? What COB? k? Driver? I think I would rather go for less cobs with more w to save money in the beginning. If that would even be true.. How much $ approx for the setup you suggest?

My other option is a Mars Hydro 600 LED Grow Light Panel Full Spectrum 272±5%True Watt for $170 which will only cover about 3x3.

Will I save money building one of these for my purposes described? If they're about the same price why build one? What are the advantages. Is it all about efficiency?

I know I could probably find most of this by scouring the internet more but I have been and it's kind of hard to figure out by myself. I'd really appreciate any help. Thank you!

Lol you got alot of questions into one post :)
The cobs will be alot more money then a mars panel.you get what you pay for.mars uses shitty drivers and lots of small led which makes more heat and less photons than cob panels or diy builds. For a 4 x 4 i seen guys put 16 cobs in there and others use just 9
Yes the drivers dictate the watts of the cobs.so if you run a 36 v cob at 1050ma its around 35watts take the volts (36) x amps to estimate your watts. So if you drive them at 1.4amp your will push the cobs to about 50w.read everything you can here posted by @SupraSPL and even @REALSTYLES they have probably covered most of your questions. Realstyles has a diy thread here also.peace

Is there a general rule for how many cobs per sq ft for flowering six?

fishwhistle said:

Is there a general rule for how many cobs per sq ft for flowering six?

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You want at least 30W/square foot. You can run a single COB at that power or you can run a COB at 150W and use less of them. Lower the power, higher the efficacy.

fishwhistle said:

Is there a general rule for how many cobs per sq ft for flowering six?

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Toaster79 said:

You want at least 30W/square foot. You can run a single COB at that power or you can run a COB at 150W and use less of them. Lower the power, higher the efficacy.

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Yeah what toaster said is what i have also read.30w a sq ft.so im running mine @35w and using 12 in spacing so ill be above the 30w rule but still driving them soft for better effeciency and longer life,in theory lol.i run my shop at 50w per sq ft now so if these compete at 35w ill be happy as hell.

Thanks for the response
Ok so is this right? whatever I'm hooking up would have x amount of volts required to power it and that wouldn't change unless I added or removed lights. Then the amount of amps I was pushing would determine the wattage in each?

Im still not sure about the 3000k/6000k. I read that it's color temperature and from the chart I see it's going through greenish blue to pink. Im confused because it also seems to represent the intensity of the light. Wikipedia has a picture of two bulbs with the same wattage but different K and the higher one was brighter. So is this more of an intensity or color thing? How can you have more intensity or k while pushing the same amount of power? Just how it's built or what? If k does have to do with color why is it measured differently than nm. Do they correlate and if so how? From what I read about nm it's the measurement of the wavelength which would determine color? Im still confused why none of these posts I seem to remember ever say anything about nm to describe COBs but every single "regular" LED grow light I see does and nothing of k.

I'm learning a little at a time it's just since all is new I learn little bits and then let's say if those bits were all cars in my head coming from different directions, going to the same point and when they get there the concept will completely make sense well, they all just smash into each other when they get there and I still don't understand shit haha. I think I have the very basics.

Still not sure about bins either

Why would someone run 16 for a 4x4? isn't that overkill or would they just run them super low to make it really efficient? I was thinking of running four CXA 3070's at 80w. Would this work?

Anyone know of a complete beginners guide that will explain all of this in simple terms so I could quit peppering you guys with a thousand questions? lol

Temperature



Wavelengths



Tint (binning)



Spectrum at different temperature

THANK YOU!

So they are full spectrum and the higher temps have more blue and lower temps have more red. I think I got that part now to try to understand bins.. I'm not even sure if I truly need all of this info but once I start learning about something I want to know exactly how everything works /what it stands for so I can make the best decision.

They explain binning and colors vs lumens pretty well on the site.

In case anyone else was wondering or got here from a browser searching for what bin is "binning is a physical sorting of LED lamps of similar brightness and color"

Thanks sixstring I don't know how I didn't find that before

That link didn't go directly to the info here's the pdf if anyone else needs it:

Every time I figure one thing out there's some other thing I've never heard of. Black Body Locus? Seriously? What the fuck? Guess I'll look that up now too lol ;):smoking:

just know that most guys are using cree 3590 cd bin in the 3500k color for bloom.and alot of thos same growers are using the same color for veg asd well.its kinda like the new 315 lec lights in a 3500k color,they are good for all stages of growth.yes you can veg with higher k like 5000 or 6500k and flower with 2700k more like hps and mh.but the 3500k does it all.its a broader spectrum than you would think

The LED Academy is a good place to start for the basics:


"The black-body curve (Planckian locus) defines the range of color temperatures, from warm (reddish) to cold (bluish), within the CIE 1931 color space."

If you are going diy you should just line atent with strips of these.

They cost very little to run and there are some grow threads on here with expensive versions of these same leds pulling pounds of top shelf out of a very small area because it has top to bottom lighting, no larf.

str8smokn said:

View attachment 558993
What would the output be on these?
STR8

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About 175 to 225 watts from what I have seen on a multi meter. I used one next to mars refletor series, and the cob easily outperformed the mars. The exact model you have pictured there. It is great for a first grow on a budget. That side of the plant was about 5 to 6 inches taller than the mars side. I run high pressure aero, and I'm bout to build two lights using the 3590s. Five per 43 inch by 6 inch heat sink. With two 200 mm fans. Mw hlg 240 will power 5 cobs at 50 watts each. Running the 36 volt@1400 mah. Thanks to supraspl, and realstyles. I have a background in electronics, so building this was as simple as ordering the parts. One question. What about my extruded heatsink from heatsink usa ? It's not flat, and I was wondering how much of a difference it makes on the thermal transfer if the surface you mount the cob to isn't flat ? Also, after this grow, i would like to build 4 more lights for a total of 30 3590s at 50 watts each over 32 Sq ft. I also plan on making a screen to help get even light distribution to most of the buds. Is this overkill ? Would 25 cobs be a better idea with the scrog ? I ordered my cobs, cob holders, reflector holder and reflectors from Jerry @ kingbrite. He was very helpful and the reflector option with all listed above and the 3590 is $48.10. The 100 mm lens option with the cob and cob holder is $51. Dhl had everything here in six days from the day I ordered. That was for 3500 kelvin 3590 with the cd bin. I also noticed where some of you are using 55 to 60 rh in your grow room. With led lighting you only need 40 percent rhythm the whole grow. I noticed more nutrient uptake and faster growth when I brought my humidity down. This lowering of humidity may help with oxidation on the aluminum heatsinks. Again, shout out to realstyles and supraspl for your amazing contributions to the led growing world.

3N1GM4 said:

If you are going diy you should just line atent with strips of these.

They cost very little to run and there are some grow threads on here with expensive versions of these same leds pulling pounds of top shelf out of a very small area because it has top to bottom lighting, no larf.

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The best bin versions of hose strip lights you speak of is about 75 lumens per watt, a little better than a mars hydro reflector ( 55 lumens a watt ). But the cxb 3590 at 50 watts is abut 173 lumens per watt. So, do some research before thinking that something is better. Check to see the efficiency of the light, and that will tell you how much of your power is being converted to photons. The best efficiency that I have been able to find data on is the cxb 3590. There may be a few smaller chips that will yield 180 lumens per watt, but the fact that you don't have to wire up many cobs is another obvious advantage. That and the meanwell Driver solution. All top shelf build components make for one bad ass light.

jdb420 said:

The best bin versions of hose strip lights you speak of is about 75 lumens per watt, a little better than a mars hydro reflector ( 55 lumens a watt ). But the cxb 3590 at 50 watts is abut 173 lumens per watt. So, do some research before thinking that something is better. Check to see the efficiency of the light, and that will tell you how much of your power is being converted to photons. The best efficiency that I have been able to find data on is the cxb 3590. There may be a few smaller chips that will yield 180 lumens per watt, but the fact that you don't have to wire up many cobs is another obvious advantage. That and the meanwell Driver solution. All top shelf build components make for one bad ass light.

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The lumen per watt only matters in lighting cost and no matter the lumen per watt you are still going to be using less energy than a big grow light even if you have to use 6 different 12v power supplies. The led strips I linked were just ones that I found to link, I would shop around for the brightest and best deal.
The reason I linked this is because tommy trichome is killin it with yield and potency from some very expensive versions of those led strip lights. He will tell you that his lights will grow it better because the strips dont have resistors but until someone does a grow log with regular cheap led strips that dont do well, I will believe that you could get the same results or similar with regular led strips.
https://www.thcfarmer.com/community/threads/introducing-the-sun-cloak-vertical.76703/

So the led strips without resistors are more efficient than those with them? Interesting. What's the role of the resistors on 12V application where LEDs are wired parallel?

Lumen/Watt ratio tells you the efficiency of light source and it also tells you the total ammount of emitted light at certain power under certain condition. The ammount of light per surface is usually mesured in lux. Lumens can also be measured but that is done in an integration sphere.

Cree anounced a led with 200lm/w efficiency years ago. Its called MK-R. Ofcourse the numbers are only reached in lab. Not long ago Cree also anounced third generation of their XP-G pushing 193lm/w if we're talking smaller 5-10W chips.

Toaster79 said:

So the led strips without resistors are more efficient than those with them? Interesting. What's the role of the resistors on 12V application where LEDs are wired parallel?

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If you push 12v through a typical led you'll cook it. The resistor is a current limiter/voltage divider. Resistors only create heat...no light...hence the drop in efficiency (lumens per watt).

That's why constant current drivers excel in efficiency.