Help choosing a light

[LittlePablo]

Im starting a hydroponic operation using DWC, now my hardest decision is choosing which lights to go with. Forsure LED and ive narrowed down my options to 4 brands. BlackDog, Advanced LED, G8 LED, or Kind LED....possibly amare technologies as well. What would you guys recommend?

[Sheesh]

I only have experience with the light I bought but I wanted to post it because it's been excellent and I would recommend it to anyone. I use the California Light Works Solar Storm 440 in a 4X4. Plenty of power to flower 3 photos in a scrog. With that said, the lights you listed are top of the line from what I've read. I know many people love the Kind and Black Dog brands.

[OzBud]

GWE Recommends:

ViparSpectra

Advanced Platinum

HydroGalaxy

Kind LED

[9fingerleafs]

Noooooo. The best technology are white COBs. Check out pacific light concepts

[DrPhoton]

Chip on boards are not as practical as they make out to be, they put out a bit of heat due to their proximity between diodes. This reduces its efficiency and lifespan more quickly. Their output efficiency does not seem to cut it with the best as well, although they are very efficient. SMD still outperform. Choosing COB over SMD from a manufacturers POV might come down to cost but from a consumers POV, theres really no incentive. COB has its purposes but unless it saves you a lot more money, cant see the reason for choosing it.

[9fingerleafs]

I was thinking more in the realm of specte. I've seen comparisons with the same strain under hps, apaches, 4Ks and COBs and the grower talk a lot about the shape and size of the buds. They were all clones they all produced the same but some bugs were rounder and some were denser. The white COBs made bigger colas than the apache and 4K. Very close to a 1000w hps. using 600wats

[DrPhoton]

Spectrum is importent yes, but its not exclusive to cob technology. Cob is an integration of many SMD leds, so whatever cob can do, SMD can do. Sometimes better because its not as limited by choice and design limitations. Spectrum king for example is a full spectrum SMD grow light using cree chips. Their light output is "white" with a very good spectrum balance suited for plant growth. Very well designed, very efficient.

[9fingerleafs]

Yes those cree are the ones I saw. Fascinating stuff

[Soilscience]

Second on the COB LED. If you are handy, build your own. Nothing is better.
Just installed one for a friend who was using Kind and other LED lights. No comparison. He just sent me a text, "I only have one word for the new lights- Kapow!"
I'm testing COB lights in 3 locations right now. The only competition is the ceramic metal halide, which is an awesome light as well. But the COB is a little more efficient, and don't need new bulbs for 5 or more years!
You are going to put a lot of money and effort into this, spend a little extra on the most important piece, the light. So it's COB, or at least LEC/CMH.

[DrPhoton]

Ceramic metal halide is not more efficient than HPS, although it is a good replacement choice as a vegging light compared to metal halide. LED is also not automatically better, as far as comparing to HPS. A great deal of grow lights are only "as" efficient but not better, with a large majority actually being less efficient.

LED manufacturers use incorrect testing parameters and incorrect advertising. They are severely inconsistent compared to eachother and a lot of products offer no efficiency benefits over traditional HPS.
They advertise the spectrum, comparing it to the incorrect chlorophyll disolved in solvent charts. Completely ignoring the Mcree curve. Whats highly amusing is with a video by kind LED in which they detail the mccree curve but then completely contradict it with a chrolophyll solvent chart.

Mccree Curve

Chlorophyll Solvent Chart

LED efficiency is not stagnant, their efficiency has been developing over the years, this is called the haitz's law. Its only of the last decade that LED technology has really seen its place as the dominent light source due to lower cost and efficiency.


Green LED's have had poor efficiency compared to RED/BLUE. The reason behind not using green in LED grow lights is not because of plant absorption sensitivity, but because its less productive using a lower efficient spectrum LED.
Recently green LED's have now caught up, allowing its use in grow lights. Spectrum king is one of the first to adopt this and has full spectrum LED products. Knowing full well about the plants spectrum sensitivity, providing highly efficient and field tested yeild per watt.

[Soilscience]

Hey DrPhoton agree with a lot of what you are saying. Many of the issues surrounding LEDs are the misinformation and marketing claims. The truth is sometimes hard to get except by actually purchasing, plugging into a watt meter, and then comparing grow results... Which could take years.
I have tested watts and par meter readings, and to a lesser extent growing with with Bridgelux 7th gen COB, cheap LED, and LEC. All of my experience with HPS is second hand. My take away is that the PAR with high quality Phillips LEC bulbs is better watt for watt than HPS. But like everything, there are differences between one bulb and the next.
Part of the wonderfulness of COB is the dimming, another is the no bulb to burn out. These are big efficiencies!
A 600 watt COB will compare to a 1000 watt HPS in many ways. But it will cost 2x as much if you build it yourself, or 4x if you buy from a reputable US builder. In a 4x4 setup you will rarely use the COB at 600. The average usage over a 16 week grow is closer to 300-400 watts. But if you are using a 1000 HPS, you are only running it for the flowering I would hope. Still, it will cost you twice as much in electrical, and new bulbs aren't free. Is the bud a little denser? That will probably be debated for another 20 years. When LED has replaced HID completely, those of us still alive will sit around talking about how great HPS weed was...
Peace.

[DrPhoton]

Yes, as far as looking at provided specifications, you cannot get reliable comparison data. However, you can compare a lights efficacy (not efficiency) with "correct" testing parameters. One particular system uses integrating spheres, collecting all light energy and captured by a sensor. This is how lumens are measured with lights. However the typical tests done today are pointless because they do not measure a lights "total" energy output. Such as using quantum meters measuring in PPFD. What should be measured is PPF.
PPFD measures the irradiance of a particular surface area (usually per 2m) which only gives you information on the light hitting a specific area. If light was uniform in all directions this would be fine, but with artificial light at close proximitys this is not the case. PPF collimates all light to a sensor, measuring all light usable by a plant.

Although common practice by grow light manufacturers is to not provide this information (because it would truely show their weakness) commercial industries that strive to improve their horticulture efficiency, commonly study the efficacy of light technology. There have been massive studys on the efficacy of lights and they are the most accurate and detailed comparing technologies.

Economic Analysis of Greenhouse Lighting by Jacob A.Nelson, Bruce Bugbee is a good study.

The next best method is probably measuring different sample points from a given space a light covers, then averaging it. This for me, combined with knowledge of the spectrum, would be enough to conclude the differences between lighting products. I personally would look at that data than a comparison grow as there are less variables to worry about. Having both would be a bonus.

[9fingerleafs]

I wanna recommend "monster gardens" on YouTube. They do those comparisons in a very profesional manner. It is worth the watch

[DrPhoton]

Yes they are relatively pretty good, the foreign person who does the testing has some really good understanding on light physics. I wouldnt listen to too much of the other guys however, they make too many theoreticle mistakes for my liking.
They do however compare CMH to MH and show that CMH does struggle to even compete with MH.

[Soilscience]

Great discussion. The lights I'm building right now are tested, but not for total output as that number can be misleading as well and is very difficult to quantify without some pretty fancy equipment.
I test on a grid laid out the size of the grow space. PAR is measured in uMols/M/s for every 3in square. The lamp is set at different heights and wattages and the entire grid is mapped at each setting. These PAR maps are then used to predict the settings to be used during the grow as plant size changes, and hours of daylight change.
Here's a pic of the test space. Crude but effective.
I have my current grow up on this forum using a similar light, but the current one has 10 3w 660red added to see what the difference might be, and to basically have some fun.
As soon as I figure out how to post a link, I'll do that. But if you want to see it it's titled Thank you GWE! My 4th indoor grow. Or something like that.

[Soilscience]

http://forum.growweedeasy.com/forum/growing-community/105722-thanks-gwe-my-4th-indoor-grow

[DrPhoton]

Personally i cannot see anything misleading about measuring total energy output of a light source, this gives you good information on the electrical efficacy and efficiency characteristics and allows you to compare, reliably between sources.
Measuring on a grid is a satisfactory way of comparing light sources, just make sure you average out the canopy and not isolate on the peak values, as the inverse square law does not apply with all typical light sources at close distances. Especially with reflectors and lenses. A light source with a higher peak value compared to another does not mean it has higher intensity, radiance or radiant flux. PPFD or lux measure irradiance or illuminance, which is only useful if the light being measured is uniform in all directions (sunlight). PPFD is measured in meters squared, although sensors are not obviously that big, they have mulipliers to compensate for its relative size.

[Soilscience]

Correct. I use the grid because it gives me the Photosyntheticly Active Radiation at each place in the horizontal space of a theoretical canopy. The problem with the total light efficiency number comes in the form of distribution. How is the light getting from the source to the leaf. How is the distribution within the grow space. How much is absorbed by reflectors. By testing the finished appliance on the exact area of usage, I come up with very applicable information. I target the range 300-800 micromols per meter squared per second. For instance, at 9in above the canopy, and at 100w, I get my target PAR density on an area about 40in by 12in. Which is plenty of room for the first 4 weeks from seed. Once in the tent and live plants, it will vary, but it is a very useful target. By the end of an 8 week veg, I will be at 14in above canopy and around 200-225w. I will have cut my electric bill by 50%, based on a 300w LEC, and even if I run it wide open for the remainder of the grow it is still a 25% savings. But so far I'm finding that even at 20in, the 300w is too much, which is good, because it means I have excess light to lean on as the system ages.
Theory is a lot of fun. But all the tools are fallible. I could have way too much blue light but the PAR meter would read the same. That's why testing several grows will be important to figure this stuff out.

[DrPhoton]

Thats not really a problem with the total light energy measurement, the information is still useful for reasons given previously. When trying to asses for specific applications, it is dependent on the design. For which the test method of measuring canopy data points is helpful for understanding its distribution characteristics but not the efficiency or efficacy of the technology itself.

Maybe this might interest you

http://forum.growweedeasy.com/forum/growing-community/102486-grow-light-height

[LuckyAcres]

I plan on doing a comparative vid on this soon but I use viparspectra led 1200 on half my grow and sun system lec 315 on the other with small overlap in between, so far the differences are so minimal I couldn't tell you which one is best, other than initial costs, about same for both, $400 ish, and real power draws (560w for led vs 340w for lec).

[NebulaHaze]

I just cannot wait for your video! This picture is really cool too! It's neat to see the results from someone growing with two of the most popular alternative lights to HPS

[LuckyAcres]

Hey hey Nebula! I'll get started soon but will wait until cure is done for full burn report as well, gotta remember to harvest both sides separate!!!!😳😳😳😳😳😳

[NebulaHaze]

Lucky, you do so much for the community! Documenting things and making videos is definitely more work than just doing it, and we appreciate all that you and Green do for us!

[D.A.A.S.69]

Mighty pretty Lucky.

[LuckyAcres]

Thanks daas! Much appreciated!

[9fingerleafs]

It looks magnificent. Great work my friend

[LuckyAcres]

Thanks 9! Gonna need helpers smoking all this for sure!