ttystikk
Well-Known Member
The business model of selling people things that last and impress is much stronger than the charlatan's alternative, and is in fact my plan when I start my own.
Think ive been led astray
- Thread starter leds420
- Start date
BobCajun
Well-Known Member
How were you using the Specrum Kings? Did you have them at least 18 inches from the plant tops and reflective sides around them? I've seen several videos and forum threads where people did get a pound or close to it per light. There's nothing wrong with using LED high bay lights to grow plants. White LEDs do work for plant growth (see article) and have a pretty good specrum for it if you look at the graphs. Here's the graph. SK lights have the red line spectrum, I saw the meter readout under them and it matches exactly. They're running 4000k neutral whites. As you can see in the graph, they have more blue and red/far red than HPS. HPS light is 73% infrared, in other words heat. That's why it burns the fuk out the plants and heats the growing chamber up like a blowtorch. With the high bays, all the heat comes from the top of the fixture and is conducted away by the heatsink fins. If you put those fins outside the top of the chamber with the reflector part sealed inside the top you would have virtually no heat going into the chamber, no infrared light at all.
SK actually charges a reasonable price for their high bays, if you look on eBay or elsewhere. In Alibaba they look cheap but that's because you have to buy a crapload of them at once and you have to pay about $200 each for shipping from China. On AliExpress where they're sold in small amounts or singly, they're about the same price as SK with the shipping added on. If you can find another US source for Cree LED high bays with lower prices than SK then take it. I haven't found any. Those lights will work if you use them right. You could also use a different power supply to drive them at 1 amp and you'd get about twice the output with less than twice the reduction in efficiency (see here). The heat would increase so you'd probably have to put a fan on the fins to cool it but it would work.
Now regarding the DIY lights that are supposedly better, how much does it cost to make them? How much trouble is it? Where do you get the LEDs and where are the test results showing that they work better than neutral white Crees? I haven't seen anything in this thread other than vague claims and unsupported assertions that Cree Led high bays don't work well for growing Cannabis. Lots of people say otherwise so the onus is on you to prove the contrary. They're definitely a whole lot brighter than red/blue type LED lamps and have a better spectrum. True that red and blue are a bit more efficient than whites, which are really just blues with added phosphors, but they don't put out anywhere near the total PPFD as the high bays. I saw the meter readings. You can see for yourself here. Granted, the high PPFD readings are under the middle of the light but red/blue type lamps don't have that intensity anywhere. You could just use a light mover to move the light around.
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Stephenj37826
Well-Known Member
I've seen people hit an elbow with a 400 h.p.s. SK is a rebranded Chinese light that cost less than 600 a piece including shipping per single unit. Stop with the bullshit. So tired of you lazy fuckers trying to bullshit people with this crap. If SK is so great post a 4x4 grid and video showing the readings. Why don't you tell people the ppf or ppfd? FACTS outshine sales pitches all day to the experienced people. Go feed on the poor innocent newbs somewhere else. Oh and BTW ppfd isn't measured in one spot. It's average over a given area.
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BobCajun
Well-Known Member
Cree cobs are exactly what the high bays are, so you just promoted them. WTF did you think they were? What is xbd? And I only mentioned the SK brand name because the original poster said that's what he used. I'm talking about 90 degree reflector Cree LED high bay lights, sometimes called stadium lights. What exactly is your problem with them? And where are the grow tests with these DIY lights? Give me the thread link and I'll see if they're actually any good.
Abiqua
Well-Known Member
Incorrect.....CXA/CXB cobs [Cree] are not what the High bays use....
This is the bin type, you know that displays things like Amperage, Volts and Heat distribution Characteristics....Kinda important, actually the most important thing really, and that you are ignorant of it and spouting off about it, is telling......
http://rollitup.org/f/led-and-other-lighting.124/
Michael Huntherz
Well-Known Member
This is a COB
http://www.cree.com/LED-Components-and-Modules/Products/XLamp/Arrays-NonDirectional/XLamp-CXA3590
Notice it says 150W peak? Not a typo. Not at all the same as Cree 5 Watt LEDs, Technically COBs should be referred to as LESs - Light Emitting Surfaces, as I understand it. But they are the latest and greatest LED tech, essentially, and they rule with an iron fist. Can I get a hell yeah?
Here's a COB DIY thread. Check the videos.
https://www.rollitup.org/t/realstyles-2nd-white-power-led-grow.876995/
In another year there will be no more discussion about LED vs HID in terms of quality per watt, grams per watt, heat management or light penetration. COBs destroy HID watt-for-watt.
When the prices come down to the point they are affordable to manufacture products with it will be over for HID. Until then the COB DiY folks will silently rule. I can't wait to join their ranks.
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cdgmoney250
Well-Known Member
I will be doing this in the coming weeks. Not paying for it, but I will do a 4x4 test with par readings, see what the footprint really is and average ppfd. Hopefully that will put all this speculation to rest. Looking about 3 weeks or so.
Btw I think we are getting an SK400+ with the 90 degree reflector.
Getting the propagation lights as well. We shall see.
BobCajun
Well-Known Member
I know the 4x4 surface won't be evenly lit. You would actually need a refractor below the parabolic reflector to spread it out. The intense part is only under the middle. But you should be able to modify the high bays to work well for growing, with a refractor or whatever. The grow area should actually be circular rather than square too, to match the shape of the beam. A circle 3.7 feet across would be 1 square meter.
cdgmoney250
Well-Known Member
^^^ I'm not sure these lights were designed with the intention of covering a circular shaped canopy. Most grow spaces I've seen are squared in the corners, i.e. 4x4 tents, basements, bed rooms.. etc. Also, if the par/lux measurements are only adequate in the center beam of the light but degrades quickly towards the perimeter, then that would be a sub-par design IMO. What I would be looking for is HID intensity "evenly" distributed over that 4x4 with all the benefits of excellent spectrum... Much of what is accomplished with DIY fixtures. But even DIY can get pricey (compared to HID) if high efficiency is the main goal.
Stephenj37826
Well-Known Member
Not COB. Cree XBD. Look at the watts and then the lumens. Now actually do some looking and you will see the diffrence between cob and xbd real quick.
No reason to switch from hps with this one. Less efficient than 400 hps in a really good reflector.
The highest price is if you order 1. Shipping is only 150 bucks.
assume
parabolic reflector maybe around 90% transmittance.
glass cover over the reflector around 90% transmittance
refractor maybe around 90% transmittance.
you are losing at least 20% of your light. what a stupid idea (refractor), almost as dumb as a round grow space.
.
BobCajun
Well-Known Member
You're a real charmer aintcha. A round grow space is the best idea ever, if the light has a round reflector which projects a round beam.
Design the light so it fits grow spaces not the other way around.
that china premade is 100 lumens\watt
Stephenj37826
Well-Known Member
Dude save some cash and buy a cmh or 400 hps. It makes no sense in spending 1200+ dollars on that low light output at that wattage. Buy an apache tech at200 or area 51 led. For 1/2 the money you could buy 4 area 51 90 watt cobs and beat that SK all day. I'm starting a light company myself and will give honest opinions on other lights period. Also look up pacific light concepts. Cheaper and more light how can you go wrong all while using less wattage. And it actually covers a decent grow area.
captainmorgan
Well-Known Member
Sorry but you don't know what your talking about,I'm currently building a light that is over 200 lm/w and over 60% efficient.
cdgmoney250
Well-Known Member
Incorrect.... XBD is the "series" of LED chip (i.e. CXA, CXB, XM-L2, Vero 29)
Within the series of chips they are then grouped into "bins" which are chips that perform similar to one another. That is why you can have a cheaper CXB3070 for $40 (AB bin on mouser), but a higher bin CXB3070 will cost you $61 (AD bin). Same chip, different performance characteristics, different price
Abiqua
Well-Known Member
^ Thanks
brass tacks, show me in a bin in the series that has greater than 30% efficiency....so lets look at some raw numbers in THEORY, quickly..
A 400w light from SK @30% [I have heard 27%] is emitting roughly 120 PAR watts....
A Gavita top of the Line 1000w is 40% emitting roughly 400 PAR watts then take away the penalty of light arc and reflector maybe 15-20% reduction in PAR....EH????????
How does 120-150 PAR watts, trump 400 PAR watts?
Now a 700watt CXB fixture in whatever bin or kelvin temp smartass @cdgmoney250.......is running at roughly 50% Emits [Lets say for shits and giggles] = 350 PAR watts, ok, now things are starting to make sense and maybe even starting to equal the photon output of HPS...
You are using less overall wattage to emit the same amount of usable light.....IN THEORY [so you jackals won't have any teeth...] Is it crushing the HPS? Really close but wait even another 18 months....for 60% efficient chips no longer on a price fixing scheme.....
Soon the swindlers will fall into tales like carpetbaggers.... They used to make the "darnedest" claims type of shit, into the annals of history, useless fucking advertising gimickry history...
brass tacks, show me in a bin in the series that has greater than 30% efficiency....so lets look at some raw numbers in THEORY, quickly..
A 400w light from SK @30% [I have heard 27%] is emitting roughly 120 PAR watts....
A Gavita top of the Line 1000w is 40% emitting roughly 400 PAR watts then take away the penalty of light arc and reflector maybe 15-20% reduction in PAR....EH????????
How does 120-150 PAR watts, trump 400 PAR watts?
Now a 700watt CXB fixture in whatever bin or kelvin temp smartass @cdgmoney250.......is running at roughly 50% Emits [Lets say for shits and giggles] = 350 PAR watts, ok, now things are starting to make sense and maybe even starting to equal the photon output of HPS...
You are using less overall wattage to emit the same amount of usable light.....IN THEORY [so you jackals won't have any teeth...] Is it crushing the HPS? Really close but wait even another 18 months....for 60% efficient chips no longer on a price fixing scheme.....
Soon the swindlers will fall into tales like carpetbaggers.... They used to make the "darnedest" claims type of shit, into the annals of history, useless fucking advertising gimickry history...