DIYers try to recreate CREE vs Gravita?

a mongo frog

Well-Known Member
My 5x5 measurement at 3ft got 258 PPFD... not really that good for flower. Thats the recommended height.
You were way under the 3 foot mark in your side by sides under DE. Everyone who's growing under DE Has taken it under 3 feet with no ill effects. Why do you keep saying recommended heights? I assume your talking mfg?
 
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MeGaKiLlErMaN

Well-Known Member
You were way under the 3 foot mark in your side by sides under DE. Everyone who's growing under DE Has taken it under 3 feet with no ill effects. Why do you eked saying recommended heights? I assume your talking mfg?
Correct, I assume they base the recommendation off of having a shit ton of them for overlap.
 

Rider509

Well-Known Member
MediheaLed:
Also, Rider, why does it seem inconceivable that we'd use these lights for 5-10 years?
I never said that. What I said was that we'd likely never recoup the cost of an LED system based on the power savings over HID because we're all tweakers who will upgrade out systems well before the end of life of our existing LED systems. And for the record I passionately hate HPS, and have a CXB3590 based system. Each four cobs are powered by an HLG-320H-C2100B for up to 75W per COB. With 16 Cobs I can hit 1200W in a 4x4 with one COB/ft2. I'm a Cobliever.
 
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AliCakes

Well-Known Member
@Evil-Mobo yes, I apologise if I didn't clarify. I have an hps for my flower area, but with an increase in space, I feel that an increase in wattage would be necessary to maximize the space. We just don't think our a/c will keep up during Texas summers. So it seemed like a good time to go higher end LEDs. Honestly, I don't know anything about quantum boards other than the name. So at this point, my first question would be what advantages and disadvantages are you guys finding with the higher end diode choices? I see many of you using QB or cob components, but cree chose individual diodes for their head to head against hps. Have any of you tried the XP series yet? And if the best choice is the cobs, what are the advantages/disadvantages of Crees vs Citizens?

In the past couple of years, led technology has changed so much I feel very far behind.

We will probably go ahead with the HPS we own for our first flower, but the hubs and I do want to build a new, bigger, better light this year. It just seems difficult to try and catch up on the newer technology.
 

AliCakes

Well-Known Member
@CobKits The only reason I even mentioned the gravita was cree's head to head test.

For more clarity, I guess a better way to word my query would be to ask those of you that have worked with the newer technology...........COBs, QBs or Cree's XP diodes? What are y'all seeing (both good and bad) with these techs? I want a good yeild, but more importantly, I want good terpine development and to lower the heat stress issues of HPS. I want to diy, because I am a tinkering type, and I want the most even canopy I can get.

What are y'all seeing that's exciting you and why? Is sunrise/sunset color control a gimmick? Or are people actually seeing any benefit? I just feel like there are so many choices that it's hard to figure out where to start when it comes to a new build.
 

wietefras

Well-Known Member
unless you have a warehouse with high ceilings and a ton of lights gavita reflector aint all that. the Boss/ACDE from sunlight supply puts down a much more uniform par footprint and is usable at 30" (and even better than gavita at 36" as well)

http://growershouse.com/images/DE_TEST_INFOGRAPHIC.pdf
Since those test only test a 4x4 square under the light, it measures only a portion of the light. Perhaps half of it. The only thing you can conclude from those measurements is which fixture has the smallest beam angle. That says nothing about total light reflected tough and those Gavita's work fine at 30" as well.

BTW If smaller beam angle is the goal, then Gavita also has a smaller beam angle reflector that fits the same fixture.
 

MeGaKiLlErMaN

Well-Known Member
Since those test only test a 4x4 square under the light, it measures only a portion of the light. Perhaps half of it. The only thing you can conclude from those measurements is which fixture has the smallest beam angle. That says nothing about total light reflected tough and those Gavita's work fine at 30" as well.

BTW If smaller beam angle is the goal, then Gavita also has a smaller beam angle reflector that fits the same fixture.
Unless my meter is shot, there wasn't much past 4-5ft that was worth having in flower even aiming the meter at the light source. Less than 100ppf after that. To me the argument of it needing a better reflector is valid, but that just takes the PPF and distributes it better, should be about the same PPFD.
 

Rider509

Well-Known Member
@AliCakes, I've wondered about Cree's decision to use the XP line instead of their flagship CXB in the head to head with the Gavita. I can only surmise that the study was done when the XP was their best performer. The most knowledgeable (or at least the most visible) LED authorities are using COBs over discrete LEDs in their DIY builds to get the most bang for the buck. Maybe reach out to Growmau5, GreenGene, or Dirtman Dan directly. Alternatively you can post up your requirements in the thread
IF you are new to LED and want help choosing what to buy, POST HERE!

At least that way your thread won't be hijacked by people wanting to talk about the Gavita! LOL
 
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CobKits

Well-Known Member
Since those test only test a 4x4 square under the light, it measures only a portion of the light. Perhaps half of it. The only thing you can conclude from those measurements is which fixture has the smallest beam angle. That says nothing about total light reflected tough and those Gavita's work fine at 30" as well.

a good point, which kind of hearkens back to my original criticism of the cree reference study - its not measuring all the light from the gavita
 

MeGaKiLlErMaN

Well-Known Member
a good point, which kind of hearkens back to my original criticism of the cree reference study - its not measuring all the light from the gavita
We are aware that a sphere tests for all light produced within it, Hard to get a good photo with it not being open.
 

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wietefras

Well-Known Member
We are aware that a sphere tests for all light produced within it, Hard to get a good photo with it not being open.
You can also do it in a dark room like Growershouse does it, but then you'd need to measure the entire footprint. That's called "flat plane integration".

Using a sphere is a lot less work obviously, but on the other hand you don't get the light distribution pattern from a sphere.

Gavita mentioned that spheres don't work well for measuring whole fixtures. In answer to the Cree horti whitepaper claims. Not sure why not. Perhaps because Cree put the whole thing inside the sphere instead of just the bottom of the fixture on a hole in the wall.

The Bugbee team (Utah uni?) did measure a higher PPF with flat plane integration though.
 

Evil-Mobo

Well-Known Member
@Evil-Mobo yes, I apologise if I didn't clarify. I have an hps for my flower area, but with an increase in space, I feel that an increase in wattage would be necessary to maximize the space. We just don't think our a/c will keep up during Texas summers. So it seemed like a good time to go higher end LEDs. Honestly, I don't know anything about quantum boards other than the name. So at this point, my first question would be what advantages and disadvantages are you guys finding with the higher end diode choices? I see many of you using QB or cob components, but cree chose individual diodes for their head to head against hps. Have any of you tried the XP series yet? And if the best choice is the cobs, what are the advantages/disadvantages of Crees vs Citizens?

In the past couple of years, led technology has changed so much I feel very far behind.

We will probably go ahead with the HPS we own for our first flower, but the hubs and I do want to build a new, bigger, better light this year. It just seems difficult to try and catch up on the newer technology.
My 600W HPS ballast blew recently, the Blue MH is by far my favorite light source to date.

That being said I am, starting a QB vs COB grow here now.

I am using (2) 3x3 areas though. No need to apologize. I was in the heat of down south before as well, now due to some life changes I am up north but the summers will be hot here too. You will be better served in TX with LED I assure you. Environment is the biggest thing to nail down. Until then the light source is a crap shoot.

I am loving the QB but the Citizen COB's are doing well too, it will be difficult to choose later on but we shall see

IMG_20170312_004310.jpg
 

MeGaKiLlErMaN

Well-Known Member
i think thats like a bare bulb hung by itself in the first 5 minutes of its life
I know, but its still on their website so they claim those results all day... But hey Im sure they're an honest company otherwise. Just not the kind I will be doing business with.
 
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