CobKits
Well-Known Member
im not gonna dig my 400 hps out of god knows where but i assure you it is capable of illuminating an 18 x18" area uniformly at well over 3000 ppfd
Understanding COB vs HID
- Thread starter Olive Drab Green
- Start date
Olive Drab Green
Well-Known Member
Alright, what about a 4x2 or a 3x3? Again, we’re talking 241w over 3 emitters covering 18x18 each with 860-920 PPFD each. My old units, anyway. We’re not talking a single emitter in an 18x18. If one emitter produces 860-920 PPFD in an 18x18, it should be as simple as multiplying its range by 3, because there are three of them covering an 18x18 each consistently.
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CobKits
Well-Known Member
lets take a guess and say a 400W HPS is 1.3 umol/J efficiency
that will give you 400 X 1.3 = 520 PPF to work with, and is 520 ppfd applied over a square meter
4'x2' = 8 sq ft = 0.74 sq meter = 520/0.74 = 702 ppfd
3x3=9 sq ft = 0.84 sq meter = 420/0.83 = 626 ppfd
18"x18" = 0.21 sq meter = 520/0.21 = 2476 ppfd (not over 3000 like my guess above but close)
Olive Drab Green
Well-Known Member
So 702 PPFD in a 4x2. That’s less than 860-920. And my new fixture is 1013 PPFD.
CobKits
Well-Known Member
your new fixture is not "1013 PPFD" though it may be capable of applying 1013 ppfd over a certain area
thats like someone asking me how fast my new car goes and me answering "45 miles per gallon"
Olive Drab Green
Well-Known Member
Alright, whatever, fine, but what about the other part?
Olive Drab Green
Well-Known Member
If one emitter covers one 18x18 plot with 860-920 PPFD, and I have 3 emitters, should I not be able to consistently spread 860-920 PPFD over 3 18x18 plots?
CobKits
Well-Known Member
"if" if does, yes of course you can. give or take depending on efficiency you need about 100 cob watts to apply 900 ppfd to a 18x18 area, and consequently ~300W of cobs to apply 900 ppfd to a 54"' x 18" area
Olive Drab Green
Well-Known Member
Alright, that’s what I was asking. That’s what I figured. Thank you, I appreciate you discussing this with me, and I apologize if I offended you, once again.
Yodaweed
Well-Known Member
CobKits
Well-Known Member
going back to the timber link you posted, with all due respect to dan/timber, listing "1013 ppfd" as a spec of the light is completely meaningless. assuming the 466 umol/s PPF figure is indeed accurate, to apply 1013 ppfd to an area you need to control that area to a size of 466/1013 = 0.46 sq. meter = 4.95 sq ft = 27" x 27"
PPFD vs PPF can indeed be confusing
PPFD vs PPF can indeed be confusing
Olive Drab Green
Well-Known Member
Gotcha. In fact, you’re right. I missed the part where it said “Coverage area: 5sq.ft.” That’s what is covered by 1013. Which adds up to what you just said. I was focused on the PPFD and PPF and had scrolled past it.
Olive Drab Green
Well-Known Member
Olive Drab Green
Well-Known Member
I guess what I really mean is, I personally grow just 2-3 plants at a time in a personal grow in a small closet. What I’m really getting at is, for people who have small personal grows, they can achieve the PPFD intensity of 600w of HPS in a smaller space for less wattage, not necessarily with the same coverage. But the plants they do grow in the smaller space would at least be getting the light needed to grow as if it were under an HPS.
CobKits
Well-Known Member
OneHitDone
Well-Known Member
If memory serves correct you had some kind of issue last round and didn't get no product
@CobKits you win some kind of patience award for participation in this Jerry's kid arithmetic olympics
Olive Drab Green
Well-Known Member
Your memory’s wrong. What are you talking about? I showed pictures 2 weeks from harvest earlier. Clearly, you’re the retard, not me.If memory serves correct you had some kind of issue last round and didn't get no product
@CobKits you win some kind of patience award for participation in this Jerry's kid arithmetic olympics
Olive Drab Green
Well-Known Member
I had temporarily gotten thrown out of my house because my girlfriend became pregnant and had an emotional issue. Her dad cut down the plants because they were stinking up the house because I took my lights, but he did end up saving it for me to pick up. She and I realized later that she was pregnant, and that was why I got thrown out. We’re now back together.
Unless you’re talking about last February where I was growing 12 plants at a partner’s house before she pulled a .357 LadySmith on me. In which case, you’re right. I didn’t get any product from that run because the bitch was a drunk and lost her shit. I’d like to see how you react with a gun in your face, nevermind leaving with any product.
Unless you’re talking about last February where I was growing 12 plants at a partner’s house before she pulled a .357 LadySmith on me. In which case, you’re right. I didn’t get any product from that run because the bitch was a drunk and lost her shit. I’d like to see how you react with a gun in your face, nevermind leaving with any product.
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