Are LED lights worth purchasing for indoor horticultural growing? The answer, I imagine, depends on your goals as a grower, and how much disposable income you have.
DISCLAIMER ------------------------------------------------------------------------
If you have a large space (greater than 16 square feet), for most people, a combination of HID light sources like HPS are their best bet. HPS has a terrible spectrum for plant growing, but they are the most efficient in terms of lumens produced per Watt, once you go above 250W HPS. So HPS puts out a lot of light and has a lot of penetrating power, allowing you to grow tall plants with all the light they need. HPS is currently the king, this thread is explaining what LED's can do.
--------------------------------------------------------------------------------------------
In what follows, I will address LED's for the small-time grower - who is most likely to end up purchasing an LED grow light online not really knowing what their product purchased is really all about. My background is in science (physics, math, biology), and I've recently spend an excessive time reading everything about growing plants under LED's I could find. I know what I'm talking about, but I also have a lot of questions that I'll get to later in the thread.
If you are growing in a smaller space, like a closet or tent, then HID lighting may pose problems: sound and heat pollution from lights, ballasts, and expensive exhaust ventilation, air conditioning, CO2 generation, etc. Let's say you're working in 10 square feet. A 600W HPS system will give you about 90000 lumens, or 9000 lumens per square foot, which is more than ample for intense flowering. Comparably, a 400W HPS system will give you around 50000 lumens, which still works out to 5000 lumens per square foot. Pretty damn good, some estimate the absolute minimum needed for flowering is 2500 lumens/square foot (Ed Rosenthal).
For the top-end HPS systems I just mentioned, a good bulb, ballast, reflector with a cool tube will run you about 600 dollars. That's before adding in air-filtration and odor reduction. If you're working in 10 square foot base, in a tent say 10 feet high, you have 100 cubic feet, and you're going to want at least a 100CFM air mover to cycle your cabinet's air adequately and quietly. Air filtering and exhaust fanning could easily add another 200 dollars to your startup cost.
Summary: HPS 600 Watt top of the line unit with air cooling and odour filtration, rough estimate 800-1000 startup cost.
I assume a lot of you DIY odour filtration and sound-proof your fans using boxes, as observed in another thread on this forum, which would reduce the startup costs to less than 700 dollars I figure. For this initial cost, in a 10 square foot growing area, you can grow kick-ass weed which will be hard to beat, provided you treat them will all the love which these plants require.
The big question - If the wheel ain't broke (wheel ~ HPS), why fix it?
Answer - If we didn't ever try to understand the physical principles underlying wheels, we'd be stuck trucking around wheelbarrows complaining about how nice it might be to able to fly our goods across the occasional giant opposing river blocking our path.
In other words - let's understand the physics of plant lights, how plants absorb these lights, in order to determine what the optimal LED plant grow light should look like. Sound like fun?
I'll try my best to write up detailed accounts in laymen's terms of the science behind the technology, plants, as well as account on what products are already out there being sold right now. I'd like to highlight the LED vendors who are doing it right, and call into question those lights which don't work, so that as consumers we can protect ourselves and ensure the best possible future for plant growing.
Thanks so much for reading, and for contributing to this site, it's AWESOME and has been an invaluable resource for me!
Up Next: PART II Physics of light - Lumens, PAR, PPF, UV, IR
DISCLAIMER ------------------------------------------------------------------------
If you have a large space (greater than 16 square feet), for most people, a combination of HID light sources like HPS are their best bet. HPS has a terrible spectrum for plant growing, but they are the most efficient in terms of lumens produced per Watt, once you go above 250W HPS. So HPS puts out a lot of light and has a lot of penetrating power, allowing you to grow tall plants with all the light they need. HPS is currently the king, this thread is explaining what LED's can do.
--------------------------------------------------------------------------------------------
In what follows, I will address LED's for the small-time grower - who is most likely to end up purchasing an LED grow light online not really knowing what their product purchased is really all about. My background is in science (physics, math, biology), and I've recently spend an excessive time reading everything about growing plants under LED's I could find. I know what I'm talking about, but I also have a lot of questions that I'll get to later in the thread.
If you are growing in a smaller space, like a closet or tent, then HID lighting may pose problems: sound and heat pollution from lights, ballasts, and expensive exhaust ventilation, air conditioning, CO2 generation, etc. Let's say you're working in 10 square feet. A 600W HPS system will give you about 90000 lumens, or 9000 lumens per square foot, which is more than ample for intense flowering. Comparably, a 400W HPS system will give you around 50000 lumens, which still works out to 5000 lumens per square foot. Pretty damn good, some estimate the absolute minimum needed for flowering is 2500 lumens/square foot (Ed Rosenthal).
For the top-end HPS systems I just mentioned, a good bulb, ballast, reflector with a cool tube will run you about 600 dollars. That's before adding in air-filtration and odor reduction. If you're working in 10 square foot base, in a tent say 10 feet high, you have 100 cubic feet, and you're going to want at least a 100CFM air mover to cycle your cabinet's air adequately and quietly. Air filtering and exhaust fanning could easily add another 200 dollars to your startup cost.
Summary: HPS 600 Watt top of the line unit with air cooling and odour filtration, rough estimate 800-1000 startup cost.
I assume a lot of you DIY odour filtration and sound-proof your fans using boxes, as observed in another thread on this forum, which would reduce the startup costs to less than 700 dollars I figure. For this initial cost, in a 10 square foot growing area, you can grow kick-ass weed which will be hard to beat, provided you treat them will all the love which these plants require.
The big question - If the wheel ain't broke (wheel ~ HPS), why fix it?
Answer - If we didn't ever try to understand the physical principles underlying wheels, we'd be stuck trucking around wheelbarrows complaining about how nice it might be to able to fly our goods across the occasional giant opposing river blocking our path.
In other words - let's understand the physics of plant lights, how plants absorb these lights, in order to determine what the optimal LED plant grow light should look like. Sound like fun?
I'll try my best to write up detailed accounts in laymen's terms of the science behind the technology, plants, as well as account on what products are already out there being sold right now. I'd like to highlight the LED vendors who are doing it right, and call into question those lights which don't work, so that as consumers we can protect ourselves and ensure the best possible future for plant growing.
Thanks so much for reading, and for contributing to this site, it's AWESOME and has been an invaluable resource for me!
Up Next: PART II Physics of light - Lumens, PAR, PPF, UV, IR
