I was going to post this in my grow adventures however I feel that the info I have from today is a good start as I understand that not alot of people use light meters. I know its not the end all yet but it is the starting line. We have all heard that COBs can out preform any other light in the efficiency area. While I agree and have seen many results.... I trust no one. So I finally got my (cheap HydroFarm) PAR meter in the mail today (if anyone knows where the calculation adjustments are for the meters let me know) From most of the videos Ive seen there isnt much difference between all of the different meters.. Just search youtube. That brings me to the PPFD results (aka the only ones that mater) for the HPS, DE HPS, and COBS. All of these tests were in a 5x4 area and the light was 2ft exactly away. I measured every square foot. (I plan on doing more in a 4x4 but I have to rebuild the COBS for that.) 2 of the sides had reflection for all tests. (in a corner) SO here are the PAR numbers that I got out of this I was on here for my first grow and have learned alot over at RIU. If anyone wants to watch the videos as they come up.
Great work and I totally respect it but the results are biased. The cob fixtures have way better spread because of how you hung them. They are better suited for the light footprint you have. You can clearly see that the DE 1000 watter had a spot that is 2,357. Your highest COB reading is almost 1,000 points lower. Not that the cobs didn't perform impressively, they did but the outside areas of your DE fixture that are only 150, 160, and 185 clearly pulled down the average drastically from a high of 2,357. All this tells me is that in order to do a fair test you need a better designed reflector for your space on the DE bulb. The crazy low readings on the outside should be thrown out because they are obviously out of reach and skewing the overall numbers in favor of the cobs or the test should be on a lower footprint where you don't factor in the shadows in the DE space. If you did that the results would be even or in favor of the DE HPS. I understand it's way more watts, but still these don't seem like fair numbers.
Is this a Cree CXA 3590 based light? Have you noticed the 2590? It's a high density cob instead of a standard density like the 3590. It's in the same lumen range but they are only 19mm instead of 30 like the 3590. I was wondering why I haven't seen any DIY's with them. http://www.cree.com/~/media/Files/C...res/Cree-XLamp-CXA-HD-Feature-Sheet.pdf?la=en
Im not sure what you mean.. its not bias in any fashion, It is raw data. Maybe if I post the 1ft marks as well, the areas are all the same and are blocked off by panda film. Of course multiple LES will make the light have a better spread, thats the point of building a light. One hotspot isnt a good thing for the plant. Also the DE light at recommended height is kinda comical to me as I can run mine at 2ft-1.5 in a 4x4 and not have much needing to be reflected. Attached is the 1 ft measurement which tells the story much better. Also its not about a single hot spot its about how much light gets to the canopy total which is why PPFD is better than a spot measurement. Its how lights are meant to be made if you want the best results, again Im not sure that you can call them bias when they draw 200W less power.
no they are the CXB series and top binned DB 4000K cobs.. much better efficiency. Running them passively cooled on pin heatsinks. CXB3590DB36V4000K 16 COBS @1.4A ON 1.813 PROFILE HEATSINK 16 SQ.FT. CANOPY 94% EFFICIENT DRIVER @15 CENTS PER KWH Total power watts at the wall: 831.91 Cobs power watts: 782 Total voltage forward: 558 Total lumens: 154163 Total PAR watts assuming 10% loss: 430 Total PPF: 1947.9 PPFD based on canopy area: 1310.44 PAR watts per sq.ft.: 26.88 Cob efficiency: 61.03% Power watts per sq.ft.: 48.88 Voltage forward per cob: 34.89 Lumens per watt: 197.14 Heatsink riser thickness / number of fins / fin's length: 0.3in/6/0.95in Heatsink area per inch: 100.94 cm^2 Total heat watts: 305 umol/s/W / CRI: 4.53 / 70CRI Heatsink length passive cooling @120cm^2/heatwatt: 363 inches Heatsink length active cooling @40cm^2/heatwatt: 121 inches COB cost dollar per PAR watt: $1.87 Electric cost @12/12 in 30 days: $45.42 Electric cost @18/6 in 30 days: $67.88 Cost per cob: $50.17 Heatsink cost per inch cut: $0.66 Total cobs cost: $803 Total heatsink passive cooling cost: $240 Total heatsink active cooling cost: $79
I just mean it's looks like your coverage is off on the DE for the room. The reflector doesn't reach pretty much at all in quite a few of the readings so it reads super low like 150. Instead of changing the situation to get a more fair outcome the super low numbers are just included in averages when it probably doesn't represent the output in a better designed size space with a DE. It represents the results in those particular dimensions. If the same test was done in a space sized for the DE and the ideal reflector was used it wouldn't include those shadows in the totals? At the same time your coverage is perfect on the COB. It seems to be built exactly for that size space. If one light is designed to fill a specific space and the other is not the base of the experiment seems slanted. The HPS output in a given space is mostly based on the reflector. When the reflector spread makes all the difference in the world with that light you have to size it correctly. That's one reason you see all those cheap light meters around. So growers can tune the reflector to their space. Many people buy one only to go. "Holy crap!" My light isn't even reaching this plant." My buddy just did that exact thing. He ended up buying a new reflector and his output is so much better with the same light/different reflector. You clearly did stomp it. My next light will be a cree cob. It'll probably be a while though. I'll start off with a small veg version to supplement veg. I see what you mean about how a single bulb would make a hot spot compared to a multibulb fixture. LED's have a huge advantage in that arena for spread I guess. I was wondering about the 2590's because they seem to be described as a more efficient cob at the cree site if I'm reading it right. Do you recommend a particular color temp for veg in cobs?
That's true, however in the attached file I had the measurement at 2ft( the recomended height is 3ft for DEHPS) and I showed what it puts out at 3,2,and 1ft from the canopy respectfully. So I you can't claim that the room wasn't designed for DEHPS since I've ran it in a 5x5 and now a 4x4. Yes the reflector probably could be bigger to give a more even spread but the PPFD would be the same just more spread out, since the same amount of light is being pushed out regardless. This light was originally made for a 5x5 but I downsized to do a proper 4x4 comparison. The tests were all done in the same size area with the same amount of panda film on the side for reflection. There's a 1ft,2ft, and just the DEHPS at 3 because that's the recommended height to run it at... Not sure why as you're wasting light.. The 3590 is the best Cree LED but citi and vero are both good as well. Veg run 6000k-3500k for flower that all depends on what your goals are... Rosin, or buds. Blue for more rosin and 2700k for more buds.
Aren't they always coming out with new lines of lights? I know they are bragging about their new xlamp xml2 10 watt led's are 20% more efficient then the ones from just earlier this year. I'm partially just wondering that since this is very new tech and not that old if there's a big leaps right around the corner that should maybe be waited for. Even the difference between the 3070 and the 3590 is pretty huge. 3070's are max 11,000 lumens and 3590's are 16,000. Sorry if I'm thread hijacking.
The xml is an ok LED but it's an improvement that isn't as good as these and it would cost way more to use them in a light... Plus all that soldering.. No thanks. Yeah Crees coming out with new stuff soon but it will likely be a new line like cxc or something even more efficient... Idk but the point is you can make a light that's up to 70% efficient now. That's crazy. Check it out in the lead section of RIU, lots of people there know what's up.
Some updates at 2weels after the clones were established.(meaning there was more than a single root hanging in the nutes and the demonstrated good growth.) everything looks good and I'm happy with the layout so far. Mammoth P really is a wonderful thing. The photos are easy to tell which is which. I'm still thinking the COBS will kill it hands down.
awesome thread, can't wait for the results! good luck with everything! I haven't used cobs or de hps yet. I was really leaning towards de hps. I'm just worried about the heat it will produce in a low ceiling (8ft) environment. can't find a good grow journal on dehps. are all 3 lights in the same room?
Yup I'm using the winter air as the AC the DEHPS really kicks out heat Also I have 7ft ceilings as long as you have the light higher than 1.5ft about the canopy you're golden, but you have to Scrog to keep the plants low
so I get that winter air cools them during lights on, but what about lights off? im sure its still really low temps during the day, do you run a heater at lights out?
There's a temperature sensor you can get for like $60 or less that turns off when it gets to a certain temerature.. Keeps it at 83F and stays around 75 with lights off.
Only another week before flip, its just past a month, I wanted to do it when all the canopy's were full...but that's how it goes I've been waiting for the SE HPS area.The signs are great for all grow from all lights. But if you were to guess the Hot spot thats a fun game to play. Pictures are underneath.
Not quite sure on the exacts but if I go by the 1ft photo and divide by PPFD/ Area to get the real world PAR per sq/Ft COBS: 81.875 PPF/ SQ DE HPS: 43.875 PPF/ SQ HPS: 33.84375 PPF/ SQ Cost per watt used COB: 1.412 $/W DE HPS: 0.4$/W HPS: 0.15$/W But to be fair with the above metric it doesn't take into account the output of the light in a usable metric, only how much power it takes so this one is a bit... better. COBS: $0.99/ PPFD DE HPS: $0.57/PPFD HPS: $0.23/PPFD So cobs are twice as much but preform twice as well.
when i used predator mites my leaf humidity was too low for them to live. the predators come with spider mites (for food) and they made the problem sooo much worse. I'm told they take several weeks to work, but I didn't have that kinda time since the webbing was everywhere already.
i've switched from using azamax systemic in-res, to SNS209 essential oil extracts, namely rosemary oil. My next experiment will be growing rosemary in the same flood tray as the cannabis.