Cobs or QB which has better coverage

[3GT]

I think the main difference between DIY with cobs vs strips vs qbs is the complexity or simplicity of the build... i.e.

mounting 8 cobs to 8 heatsinks with thermal paste and cob holders, cutting and drilling aluminum and building a frame, and attaching the light engines to the frame
vs
mounting 22 strips to 22 c-channels, flat bars, or extruded aluminum heatsinks with thermal tape or thermal paste and screws, cutting and drilling aluminum and building a frame, and attaching the strip modules to the frame
vs
mounting 2 qbs to 1 heatsink with screws...

If I had more time and energy to build, I probably would have gone with strips, but the simplicity of the qbs was hard to beat.. so that's what ultimately made my decision

Price also is a very big deciding factor for most.

Also those strips don't need any heatsinking @700ma so its just attaching them to a frame

 

[LEDandCoffee]

I was trying to compare 100 point sources of a strip vs 1 of a cob.

I guess I don't have any desire to run 15 strips in my tent when I can just hang 3 lights and call it a day. I get your point as far as evenness, but cobs hands down have the best penetration of the 3

 

[3GT]

I guess I don't have any desire to run 15 strips in my tent when I can just hang 3 lights and call it a day. I get your point as far as evenness, but cobs hands down have the best penetration of the 3

You run 3 cobs or qbs? Don't you think you're wasting a lot of light getting so much penetration? Run a 2' f series strip @ 70w and it will throw light deep, but you're wasting light having it so far away.

 

[whytewidow]

I think all three choices grow amazing herb. Really comes down to a point of preference

 

[Nutria]

Can someone explain me wtf is "light penetration"?
Is it related to the overall "power" of the light? How can we measure it?

Multiple light sources seem to emit light from different angles reaching deeper canopy

 

[LEDandCoffee]

Can someone explain me wtf is "light penetration"?
Is it related to the overall "power" of the light? How can we measure it?

Multiple light sources seem to emit light from different angles reaching deeper canopy

How far the light can get past the canopy. Green light penetrates the furthest but is the least efficient for instance.

 

[Colo MMJ]

I would go with 24 strips @700ma (no heatsink required) split into 2 x 2'x2' fixtures each with 12 strips each.

What is your mains voltage?

What kind of driver/ballast?

 

[psychedelicdaddi]

since the diodes dont really become "stronger" when you get closer you can get crazy close to LED strips. like an inch away if your heat is under control. For sure couldnt do that with a COB. Which basically just means more head space in a tent.

 

[3GT]

What kind of driver/ballast?

Sorry my mistake with saying 24; later on I posted 22 x 2' strips paired with a hlg-320h-c700

 

[Colo MMJ]

https://www.arrow.com/en/products/hlg-320h-c700a/mean-well-enterprises

22 x 2' strips + hlg-320h-c700a

11 strips per 2'x2' fixture and you're done.

Mount them on anything?

 

[3GT]

Mount them on anything?

Just a frame to hold them all in place, no heatsinking required @700ma.

 

[whytewidow]

Sorry my mistake with saying 24; later on I posted 22 x 2' strips paired with a hlg-320h-c700

Mount them on anything?

I' mounting some an a sheet of 1/4" alum. You could mount them on anything. But he said at @700ma they didn't even need a heatsink.

 

[whytewidow]

I was looking at making cobs. Was gonna do 6 or 8 citi cluo48-1818s 3000k 90cri on arctic chiller heatsinks and fans. With reflectors. Was lookn at about 325 shipped. I bet they would flower the shit outta 2x4 tent.

 

[whytewidow]

Just a frame to hold them all in place, no heatsinking required @700ma.

I think I read they can be pushed to 1300ma

 

[Colo MMJ]

https://www.arrow.com/en/products/bxeb-l0560z-35e2000-c-b3/bridgelux

How many are needed to match a 1000 watt SE HPS for flower? Thanks mate.

 

[whytewidow]

I like the rapidled cob fixtures too

 

[whytewidow]

How many are needed to match a 1000 watt SE HPS for flower? Thanks mate.

Take the lumens of high output how is 130-150,000 lumens. I think the strips put out like 24xx lumens so it would take quite a few

 

[nc208]

You get as much height/coverage as the power you're running really. Strips should be spaced closer together near the outside/edges to do just the same. I don't see how its not better having 100 cobs (strips) vs 1 cob? In any situation really.

I prefer the opposite, I prefer 1 big 100w cob vs 100 1w leds (or 0.3w leds which samsung and bridgelux use). While yes you are correct the 100 diodes spread out will be a more even canopy I prefer the more powerful cobs which punch farther down the plant. That being said who is using a single cob to light their space? If you space your cobs correctly at the correct height you can achieve a very even canopy.

 

[wietefras]

I prefer the more powerful cobs which punch farther down the plant.

That's a common misconception though.

One big light gets largely absorbed/reflected when it hits the canopy and doesn't travel down much. The leaves are all oriented to this big source of light.

When there are lots of light points, the leaves will orient themselves to the closest ones, but the light points a bit further away can then shine under those leaves.

When you need to hang your lights at 18" to get some uniformity, then your wall losses are huge compared to a led strip fixture where 5" would be enough distance. So better distributed light will give you more light on the plants (less wall losses) and will also give you more light under the plants.

 

[nc208]

That's a common misconception though.

One big light gets largely absorbed/reflected when it hits the canopy and doesn't travel down much. The leaves are all oriented to this big source of light.

When there are lots of light points, the leaves will orient themselves to the closest ones, but the light points a bit further away can then shine under those leaves.

When you need to hang your lights at 18" to get some uniformity, then your wall losses are huge compared to a led strip fixture where 5" would be enough distance. So better distributed light will give you more light on the plants (less wall losses) and will also give you more light under the plants.

That's why I wrote spaced properly, for example my tent is 40" x 40". I have my lights on a 20" x 20" frame the cobs are spaced apart 15" OC. Very little of that light is being wasted on walls, I found best response for my plants was at a 15" distance at 75w each.

Here is my light, my last run I used strips from Alibaba, which were lm561b+ where I made a light that covered the entire area, It worked great, this time I am using a combo of strips(lm301b 5000k) and cobs and mini cobs to try a few different spectrums. I'd rather use strips for side/supplement lighting but this is just my personal opinion.

that was a month ago, here is today 10 days into flower. Growth is excellent throughout the plant. OG18 hermied so it had to go.