Cree CXA3050 100W Custom LED Grow Journal with Dinafem Blue Widow

I've been an avid grower for years, and within the past year and a half I switched from 600W HPS grows, to small scale LED grows.

For the past 18 months I have been using the Advanced LED Diamond Series 100 grow light with really good results.

However recently, I have been having issues with LEDs burning out and when one LED goes out in series, they all go out.

Advanced LED's was very nice in honoring their warranty and sent me a replacement and didn't even ask me to send back the broken one, so I decided to take apart the broken one and build me a new light using Cree's latest and most power COB led's the CXA3050!

The CXA3050 LED's put out over 5000 Lumens when driven at 1.4Amps and can get over 10,000 Lumens when driven at 2.5 Amps.

I ended up purchasing 2 LED's from digikey (CXA3050-0000-000N00W227F-ND). Digikey reports lumen output of 5683 at a color temperature of 2700K

According to the Cree data sheet, driving the LEDs at 1.5 amps gives about a 15% boost and has a forward voltage of 38V, so the lumens theoretically increase to 6535.45

Which comes out to approx 115 lumens per watt, which is as good as HPS (1000W HPS puts out 120,000 lumens = 120 lumens per watt).

OK, so with all the tech specs aside, lets put this thing to work.

Ok, after dissembling the the DS100, I decided I would need some better drivers as the DS100 has 2 drivers that run around 600mA and max 75W. I order two drivers off ebay that can run at a max 42V and constant current of 1.5 which is perfect for the CXA3050.

The picture below is of the driver I purchased

Each driver cost $18.

I also decided I would run these drivers outside of the cabinet instead of inside the fixture as that would account for less heat as well as more cooling space across the heat sink since the drivers would have taken up space and block air.

Another thing I didn't like about the DS100, was the glass in front of the LEDs. I understand the reason behind that was to keep the lenses in place, but since I would not be using lenses, I would like zero blockage from glass.

Apparently glass blocks about 7-10% of light and since LEDs do not radiate nearly as much heat as HPS lights, there really is no need for glass.

To finish things up, I used some reflective tape to round out the edges where the glass was so I would get a better reflection off the sides of the light.

The picture below is the finished product running two CXA3050 2700K LEDs inside a DS100 grow light.

Nice work....can you point the camera up underneath the fixture please?

Things are still going well. Here is a closeup at 1 week since breaking ground




Here's a closeup at 11 days



Here's a closeup at 13 days

Awesome. I'm subbed up for this

No prob, I'll take one when I get home. The LED's are so friggen bright, that I think I'll have to take it while it's off, but I'll see what it looks like while it's on as well

I made the mistake of looking at one and I had a hard time seeing for a good bit.

Update

I just got my light meter today and holy cow do these CXA3050 LED’s throw off some serious intensity.


I was getting over 100,000 LUX 4-5 inches from the LED and over 30,000 LUX around 14″ away.


I compared the 2 CXA3050 (100W Total) intensity to a 150W HPS intensity and the HPS doesn’t even come close.


I barely got 50,000 LUX if I put the light meter directly under the HPS (granted the HPS is air cooled so some intensity is lost through the glass).


I was getting 50,000 LUX around 10-12 inches with these LED’s


I am very excited to see the growth since these LED’s also have really good PAR ratings and intensity.

According to Jorge Cervantes, 100,000 LUX is absolute maximum you want at Canopy during flowering and 50,000+ is ideal

Since I will be scrogging this grow, I should have no problem keeping my all buds within 50,000 LUX and ideally 100,000 LUX at the canopy.

Yeah fair enough.....pretty easy to switch out i guess....nice easy solder.

Good growth on your ladies.

By the way I am growing hempy style with a mixture of 70% perlite to 30% coco and using the entire floranova drain to waste feeding schedule

Strain is Blue Widow by Dinafem

In the mean time, I will be modifying my clone/veg container with a 5000K CXA LED and sprout some C99's that I am extremely excited for.

I have heard nothing but amazing things on C99 and I love me a good sativa!

Nice man, should be a fun ride. Blue widow is still possibly the best strain I have ran. Big yields and awesome quality.

1000w hps do 145lm/w...but regardless looks like you canopy should be getting the ideal light. Are both the COB's 2700K?

EDIT: I just saw that both are 2700k

Correct, the digital super hps runs 145,000 lumens.

It's the old school magnetic ballast and regular HPS that runs at 120,000

Another thing to consider is that all led light is directed downward, unlike HIDs which need a reflector which loses some efficiency.

I like that I've grown with so many types of light, so I'll easily be able to see if these lights are any good, but based off my current tests, I have no idea why they shouldn't be.

Nice to hear your high regards to the Blue Widow. Dinafem has never let me down. Their crit + was amaze.

Chronikool said:

Nice work....can you point the camera up underneath the fixture please?

Click to expand...

Here's the underneath pic with the light on. I drilled some holes in the heatsink between the two lights as there is a fan in the middle of the light that blows through the holes and really keeps the heat sink cool.

In total there are three fans in the fixture with each light getting a fan over it and then the one in the middle. The fans draw a total of 9 watts

Just to clarify...we are talking about 12,000 lumens vs HPS 1000w 150,000 lumens? Right?

Lumens per watt. I have over 13000 lumens for 100w. Multiply that by 10 and I have 130000 lumens with a much better PAR than HPS.

I'm not trying to beat a 1000HPS bro. I'm growing one plant man.

The point is these LEDs from Cree offer a light intensity that is more powerful than small and mid range HPS and are getting close to high end HPS.

The data sheet for the CXA3050 recomends these LEDs as replacements for 175W ceramic metal halides.

I would consistently pull 70-90 grams off my DS100 and that was just 1 plant.

If I did a 2 plant scrog, I could easily pass the 1 gram per watt.

I love the look of the 3000k, 93 CRI graph....BANG ON! Hmmmmm...wonder where the 2700k comes in...they kind of left that out... Im really interested in these now...

bbspills said:

Correct, the digital super hps runs 145,000 lumens.
It's the old school magnetic ballast and regular HPS that runs at 120,000

Click to expand...

bbspills said:

The point is these LEDs from Cree offer a light intensity that is more powerful than small and mid range HPS and are getting close to high end HPS.

Click to expand...

Even mags 1000w'ers do 140,000-145,000lm without the overdrive feature...even more lumens but less per watt when on overdrive. The ballast do make a slight difference but it's +/- the base value of the bulb(current tech is at 145,000lm). That's why the newest cree's that break the 140lm/w barrier were/are such a big break through. Finally equal output even on the biased lumens scale.
Those cobs are still very economical and produce comparative to lower range hps like you said.

bbspills said:

Lumens per watt. I have over 13000 lumens for 100w. Multiply that by 10 and I have 130000 lumens with a much better PAR than HPS.
I'm not trying to beat a 1000HPS bro. I'm growing one plant man.

Click to expand...

The nicest thing about high power led's is that you can put 1000hps power in almost any given space with just the right wattage to achieve it and not waste. Your one plant can have 1000w buds even in a 2x2 space.

The only thing with the 93 cri 3000K is the lumen output is like 20% less.

So would you trade off less intensity for a better spectrum?

I sure did like that graph too though.

We'll have a good idea in about 10 weeks on the 2700K when I finish this round


Day 14.

Growth is starting to get rapid! Big difference from the day 13 pic. I love this part. Can't wait to see what week 3 brings. I'm glad they are vegging well under the 2700K. I can only imagine how well the 5000K LED's would do. Plus the 5000K are the brightest of all the CXA LEDs.

I think one of my favorite aspects already of this LED tech vs the blue/red LED tech is that pictures come out much nicer and natural. I hated those magenta pics my other LED made and the super yellow with lines my HPS made.

Plus my camera on my phone sucks as well, so it's nice to not have to find my digital which might be in some pile of dust somewhere

bbspills said:

The only thing with the 93 cri 3000K is the lumen output is like 20% less.

So would you trade off less intensity for a better spectrum?

Click to expand...

In this case i would as there are still a shit load of lumens shooting down and in my flower cabinet i would still be looking at around 20,000 lumens total with these....plenty in my case.