LEDs Vs LEC (Donaldj)

I recently received 2 Led cob lights I am hoping to run a close comparison grow with true Watts being extremely close and both light setups being relatively same price


Lights in contention on this test/challenge
1 Roleadro 400w full spectrum (pink) actual watts 196
1 Roleadro 400w Cree 2700k 100w conservatively
both lights together costed roughly $260 bf shipping

They will be competing with
1 Sunpix 315 LEC 3100k peak draw 345w
comparable LEC price $260

Both light rigs will be on lightrail 4.0
Light mover in separate spaces during flower Cycle
Strain under Led is White Widow in 7 gal promix

THC: 18.76% CBD: 0.10% CBN: 0.28%

Brazilian x South Indian.

A relaxing indica feeling that turns into a bursting sativa high.
Very complex and enjoyable, fast hit and long-lasting effect.

8 weeks, with production up to 800 gr/m2.
Very good for ScrOG.

Under LEC ILGM Super Skunk in 5 Gal promix

Both plants are close to same size at transition and on same feeds WW has an advantage being vegged longer than SS and in larger pot but evens out in wattage difference between systems.


WW day 1
far larger plant than SS

I suspect that by end of transition SS will be close to caught up


Since WW is starting third week in flower it has ended stretch and a point of note is Led keeps space 6f cooler


I am very interested in how the cob/led grow goes. I’m thinking about doing crees w/a pink led in there, as well.


Thank you for starting this @Donaldj I’m set to watching Sir. :v:


Great thread @Donaldj i mixed my lights using my lec in center and leds /cobs on edges
Im looking into light rails i see the benefits of them
Im watching this thread as well buddy
Proper rebuild of my grow soace will be under way in another month or so when I finish this current run :wink:
Awesome job


Cant wait to see how this goes. Im ole’skool i guess… Cant totally ditch the HID lighting. I run a 400mh/hps and 2x250watt leds on either side. Kind of like @Countryboyjvd1971 . Crazy how much things like auto’s, fast version strains, and LEDS have changed in the last 10yrs… I am thinking LEC 315 is making its way onto the “have to have” list.lol


My impression is that LECs have a better spectrum that other HID bulbs, but are in the HID realm in terms of efficiency. COBs can do better IF you drive them at about 1/4 max current. So you buy lots of COBs to begin with but buy less electricity for years. But I have not seen any proof that commercial COB lights run at 1/4 max! If you run them a lot harder, their efficiency gets near to HPS.

A better experiment would grow clones of the same mother under the different lights, with the power used by each light adjusted to be the same.


I know LED’s what’s a LEC ?


light emitting ceramic


It’s like a metal halide lamp but with a ceramic tube instead of quartz. So it can run hotter inside which gives you more and better light.


@phred also know as ceramic metal halide or cmh
Its a more natural color light and you also get the uv range which you dont get from hps


Watching as well, thanks for doing this @Donaldj.


Watching as well. Thanks.


I agree but also figure the size variance between plants should offset the 315w having any decided advantage being 30-50 or so watts more.

The other factor was cost of startup gear being close this is a test between widely avail fully assembled lights not DIY kits :wink: The Roleadro 400w FS cost $89 each the Cree upgrade $169 and all easily ordered on Amazon. Manufacturers advertise them as being able to replace 400w HID yet using less power so if that is the case how can LED growers think this isn’t a fair test 2 of them should be able to out perform a single 315w HID?


As far as I can tell, LED light manufacturers claims about “equivalent watts” is just marketing hype. I think it would be interesting if somebody would set up an experiment with clones under several different lights to see if the claimed number has any truth to it. Just looking at “watts-from-the-wall” and published spec sheets lumens per watt, they look like BS. But maybe I’m wrong and “blurple” LEDs are vastly superior.


I doubt it. I’d settle for places like amazon and retailers to require integrated sphere data if a manufacturer wanted to make any equivalency claim. Level the playing field to where people can see why one led is three times the price of another. Then we can run the side by side grows to compare known par levels and argue about which light spectrum is better haha!

I don’t don’t believe Donaldj was trying to make an end all be all statement about one technology being superior to the other. It’s more of a “here’s what you get for the money” type of grow from our earlier conversations.

You and I know the difference between what’s available and what’s in these lights. All we can do try to provide the best information we have and let the others make informed decisions. Not everyone has the funds to buy the top performers, or the ability to build them. Is what it is.


Nice topic. I’ll be tracking…


Correct that is the goal a simple evaluation of plug and play systems of similar dollar value and true wattage which gives more bang for buck without having to design or build anything :wink:
I know clones of same strain would be more accurate but I grow 3 light rotation and single plant per space I actually growing smaller than many growers :wink: favoring monthly harvests to big harvest every few months and don’t worry so long as LED’s don’t give me under half usual yield they will get another run with same strain as LEC
It just happened to be the plants I had ready and fairly equal in size