Stevehman's LED buyers guide:
I've been answering questions about which LED to buy, how to use them and which company is best for the past year. First let me say that I am not an expert in LEDs, so all of my opinions are just that–my opinions. Also, I'm not going to debate LED vs. HPS, CFL, MH etc... They all are capable of growing quality meds. This is written with the premise that the buyer has researched the other light systems and decided that LEDs are the way to go for their situation.
I have been using LEDs for the past year and have 4 successful grows under my belt and have journaled them here on 420, I try to keep a detailed record of my successes and failures so that I can track what I've done and what I should either replicate or avoid. There are so many vendors out there; I won't make any recommendations on which one to buy in this thread (if you want my opinion, just read my journals). The only recommendation I will make here is that you buy from a sponsor of the site; it helps keep the community going.
When it comes to purchasing an LED lighting unit you should do your research and know what you're goals are. Let's start with a quick checklist of information you need to compile before you start the search for the "perfect" lighting system for your grow:
Pre-purchase checklist:
1) Budget (LEDs are more expensive than other lights, about 2~3 times more than a comparable HPS system)
2) Size of grow space (both foot print and height are factors to consider)
3) Style of grow (SOG, SCROG, LST, Bush, tree etc...)
4) Cooling requirements
Once you know what your requirements are, you then need to see if an LED unit is the best value for your needs (notice I didn't say cheapest or cost effective). Although LEDs are much more expensive than other types of lights, they do have some offsets that help make up for the price gap. They require little or no cooling (depending on your space), they have a lifespan that is several times longer than other lights (CFLs are a close one though), they use less electricity, and they have a low profile (perfect for height restricted spaces). If after you've looked at all of your data you've decided that an LED is in your future it's time to decide on which unit is going to be best for you.
First let's look at the foot print. Just about every manufacturer lists their "core coverage" numbers on their sites. Take most of those numbers with a grain of salt. Here are my recommendations:
Foot Print Light Size
2x2 a single 180-240 watt unit should be adequate for this space
2x3 a single 300-400 watt unit
2x4 two 180-240 watt units
4x4 four 180-240 watt units, a pair of 300-400 watt units or a single 600+ unit
4x6 three 300-400 watt units or a pair of 600+ units
For spaces larger, just take the recommended numbers and apply them, for example a 4X8 tent would use twice the lights of the 4x4. Also when planning your grow there is a "third light effect" when using two lights. They way that works is the space between the two lights has the effect of having a third light over it. Let's say your core coverage is 2x2 and the are outside that is dropped down to 50% effective (say out to 30 inches) , if you have the light from another LED unit covering that with its "outside" coverage as well, you have 50% from each light hitting that spot and effectively having the power of a third light covering that gap increasing your overall foot print. So, when laying out you lights, take that into consideration. If you core coverage is 2x2, place your lights about 30~ inches on center from each other, your eight above canopy will be a factor in this. Place your lights into the space and adjust them prior to putting your plants in.
So you know you are ready to purchase an LED, and you know how many and what size you need, now which one to buy?
What watt is what?
This is usually the first question I am asked; how many watts do I need? First you need to understand that all watts are not created equal (will actually a watt is a watt). Watt isn't equal is how manufacturers label their units. You should look at the watts a unit actually uses and not the "watts on the board". Let's take for example a unit that has 288 3watt LED chips on the board, 288x3=864 so I have an 864 watt unit right? Nope! You have a unit that is capable of 864 watts if driven to its capacity. When you drive a unit to its max you are going to produce a lot of heat and shorten the lifespan of the unit considerably. So most manufacturers only drive their units to a fraction of that and balance the fine line of performance and reliability. So that same unit that has a board wattage of 864 may be marketed as anything from a 360 to a 800 watt light. The key here is to forget what the name is, look at the actual power draw of the unit. In my experience these units have about a 10% overhead draw for fans and power supply (so a 360 unit draws about 400watts). Beware of lights that purport to be 90watt units but only draw 18watts!
1watt vs. 3watt
LED chips come in several wattage outputs, from less than a watt up to 100watts (very expensive and experimental). The common sizes you'll see in a grow light are 1 and 3 watt chips. 3 watt chips are better suited for applications that require more penetration. If you are doing a low profile grow, or cloning then 1 watt chips will be fine. For anything else a 3 watt chip is the only way to go. Now not all 3 watt chips are made alike. There are companies that manufacture them in the US, Europe and China (we're talking the LED chip, not the light unit). It is widely accepted that the better quality chips are going to be US made, names like CREE and Bridgelux are the leaders in LED research and manufacturing)
Wavelengths:
What is best? 11, 9, 7 4 wavelengths of color? Is UV required, what about white LEDs? What is the PAR rating? All good questions, I'm not a scientist so I can only base my opinion on my own observation. I have found that the 11 bandwidth units I use do a fantastic job; they don't use white LEDs, but do have UV. They claim to have peak PAR values and without the proper test equipment I can't give quantifiable data (if anyone wants to send me a PAR meter, I will be glad to run an exhaustive series of tests on several lights).
Buy US made?
There is a lot of rhetoric about "don't buy cheap Chinese LEDs", well that is true, to a point. Almost every LED grow light is assembled in China, but where their design and parts come from is the important part. Are they using high quality powers supplies (the part most likely to fail), what type of heat sink are they using, are they using all US made chips, or just a few, or none at all?
Drop shippers vs. brick and mortar:
In the world of the internet, anyone can become a vendor. All you need is a website and a point of contact in China to accept orders and ship them for you. IMHO about 80% of the vendors in the industry (to include hydro companies) never even carry inventory. They take you order, accept your payment and then place your order with their supplier who in turn sends it to your address–all from the comfort of their college dorm room. I'm all for the entrepreneurial spirit and if your buying low cost items that won't break (net pots, nutrients etc...) then why not put some spare change into a starving college kids pockets. If you are buying something that may break and you need to call customer support and have it replaced, there is no substitute for an actual company with a real warehouse and a customer support line (that will actually be answered).
There are a bunch of "one-man" operations out there drop-shipping lights from China, and some of them are OK units. The issues will start when the unit breaks, has a faulty driver, fan stops etc... If they ask you to send the light back and THEN they will send you a replacement, that is an issue, they should send the replacement out immediately and allow you to return the light in the box the replacement came in--postage paid!
Unless you are prepared for the potential headaches, DO NOT buy LEDs from drop shippers. If they don't have them in stock and can have them to you in 3~5 days, they are most likely a drop-shipper (unless they just happened to sell out their entire inventory–which happens).
What's the word on the street?
Check out other people's journals, look for reviews, Google the name of the company and if possible the name of the owner of the company. T here is a whole internet full of information out there and if you don't take the 5 minutes to research the company that you are about to send $1,000 of you hard earned money to, shame on you. There is at least one company out there that is known to have reputation of poor customer support and going as far as calling the local sheriff's office on one of their customers because they weren't happy with the result of a customer service dispute (avoid any company that has threatened to put additional charges on your credit card, or that they will call LEO and report your "illegal" grow, sounds odd, but it has happened).
Read grow journals that have the lights you are interested in, when possible look for comparison grows. Beware of company's own website testimonials unless they're linked to a known grower. Check out YouTube as well for grow information, but again, be aware that some companies are posting their own videos and passing them off as satisfied customers.
Research the company. How long have they been in business, check out the whois.net to see when they registered their company site, where they're located etc...
Do you own research and make your own decision. At the end of the day you are the one that pulled the trigger and spent the money and the one that will have to live with the results if your decision was made in haste.
When you do decide to make a purchase, here are some questions you want to ask the company:
1) How long is your warranty?
2) What is your replacement procedure?
3) Are your units in stock, or do you drop-ship them from the factory?
4) How many employees do you have? (some companies claim to have in-house scientist, ask for their credentials if they are making that claim. Some one-man operations are fine, but then one person is taking, filling and shipping orders and handling customer service)
5) Ask for details on the light, number and type of chips, actual wattage, recommended core coverage and height above canopy etc..
6) When will this unit ship, and when can I expect to have a tracking number?
I am sure that you have more questions now that you've read this, that's a good thing. It means you're doing some critical thinking. Now it's time to do some homework of your own, fire up the search engines, crack a book or magazine article open and make and informed decision. If you find some information to share feel free to put it here. The only thing I ask is that you keep everything here company name free and not make specific endorsements on a manufacturer. If you want my recommendation I will send it via PM (or you can read my journals)
I've been answering questions about which LED to buy, how to use them and which company is best for the past year. First let me say that I am not an expert in LEDs, so all of my opinions are just that–my opinions. Also, I'm not going to debate LED vs. HPS, CFL, MH etc... They all are capable of growing quality meds. This is written with the premise that the buyer has researched the other light systems and decided that LEDs are the way to go for their situation.
I have been using LEDs for the past year and have 4 successful grows under my belt and have journaled them here on 420, I try to keep a detailed record of my successes and failures so that I can track what I've done and what I should either replicate or avoid. There are so many vendors out there; I won't make any recommendations on which one to buy in this thread (if you want my opinion, just read my journals). The only recommendation I will make here is that you buy from a sponsor of the site; it helps keep the community going.
When it comes to purchasing an LED lighting unit you should do your research and know what you're goals are. Let's start with a quick checklist of information you need to compile before you start the search for the "perfect" lighting system for your grow:
Pre-purchase checklist:
1) Budget (LEDs are more expensive than other lights, about 2~3 times more than a comparable HPS system)
2) Size of grow space (both foot print and height are factors to consider)
3) Style of grow (SOG, SCROG, LST, Bush, tree etc...)
4) Cooling requirements
Once you know what your requirements are, you then need to see if an LED unit is the best value for your needs (notice I didn't say cheapest or cost effective). Although LEDs are much more expensive than other types of lights, they do have some offsets that help make up for the price gap. They require little or no cooling (depending on your space), they have a lifespan that is several times longer than other lights (CFLs are a close one though), they use less electricity, and they have a low profile (perfect for height restricted spaces). If after you've looked at all of your data you've decided that an LED is in your future it's time to decide on which unit is going to be best for you.
First let's look at the foot print. Just about every manufacturer lists their "core coverage" numbers on their sites. Take most of those numbers with a grain of salt. Here are my recommendations:
Foot Print Light Size
2x2 a single 180-240 watt unit should be adequate for this space
2x3 a single 300-400 watt unit
2x4 two 180-240 watt units
4x4 four 180-240 watt units, a pair of 300-400 watt units or a single 600+ unit
4x6 three 300-400 watt units or a pair of 600+ units
For spaces larger, just take the recommended numbers and apply them, for example a 4X8 tent would use twice the lights of the 4x4. Also when planning your grow there is a "third light effect" when using two lights. They way that works is the space between the two lights has the effect of having a third light over it. Let's say your core coverage is 2x2 and the are outside that is dropped down to 50% effective (say out to 30 inches) , if you have the light from another LED unit covering that with its "outside" coverage as well, you have 50% from each light hitting that spot and effectively having the power of a third light covering that gap increasing your overall foot print. So, when laying out you lights, take that into consideration. If you core coverage is 2x2, place your lights about 30~ inches on center from each other, your eight above canopy will be a factor in this. Place your lights into the space and adjust them prior to putting your plants in.
So you know you are ready to purchase an LED, and you know how many and what size you need, now which one to buy?
What watt is what?
This is usually the first question I am asked; how many watts do I need? First you need to understand that all watts are not created equal (will actually a watt is a watt). Watt isn't equal is how manufacturers label their units. You should look at the watts a unit actually uses and not the "watts on the board". Let's take for example a unit that has 288 3watt LED chips on the board, 288x3=864 so I have an 864 watt unit right? Nope! You have a unit that is capable of 864 watts if driven to its capacity. When you drive a unit to its max you are going to produce a lot of heat and shorten the lifespan of the unit considerably. So most manufacturers only drive their units to a fraction of that and balance the fine line of performance and reliability. So that same unit that has a board wattage of 864 may be marketed as anything from a 360 to a 800 watt light. The key here is to forget what the name is, look at the actual power draw of the unit. In my experience these units have about a 10% overhead draw for fans and power supply (so a 360 unit draws about 400watts). Beware of lights that purport to be 90watt units but only draw 18watts!
1watt vs. 3watt
LED chips come in several wattage outputs, from less than a watt up to 100watts (very expensive and experimental). The common sizes you'll see in a grow light are 1 and 3 watt chips. 3 watt chips are better suited for applications that require more penetration. If you are doing a low profile grow, or cloning then 1 watt chips will be fine. For anything else a 3 watt chip is the only way to go. Now not all 3 watt chips are made alike. There are companies that manufacture them in the US, Europe and China (we're talking the LED chip, not the light unit). It is widely accepted that the better quality chips are going to be US made, names like CREE and Bridgelux are the leaders in LED research and manufacturing)
Wavelengths:
What is best? 11, 9, 7 4 wavelengths of color? Is UV required, what about white LEDs? What is the PAR rating? All good questions, I'm not a scientist so I can only base my opinion on my own observation. I have found that the 11 bandwidth units I use do a fantastic job; they don't use white LEDs, but do have UV. They claim to have peak PAR values and without the proper test equipment I can't give quantifiable data (if anyone wants to send me a PAR meter, I will be glad to run an exhaustive series of tests on several lights).
Buy US made?
There is a lot of rhetoric about "don't buy cheap Chinese LEDs", well that is true, to a point. Almost every LED grow light is assembled in China, but where their design and parts come from is the important part. Are they using high quality powers supplies (the part most likely to fail), what type of heat sink are they using, are they using all US made chips, or just a few, or none at all?
Drop shippers vs. brick and mortar:
In the world of the internet, anyone can become a vendor. All you need is a website and a point of contact in China to accept orders and ship them for you. IMHO about 80% of the vendors in the industry (to include hydro companies) never even carry inventory. They take you order, accept your payment and then place your order with their supplier who in turn sends it to your address–all from the comfort of their college dorm room. I'm all for the entrepreneurial spirit and if your buying low cost items that won't break (net pots, nutrients etc...) then why not put some spare change into a starving college kids pockets. If you are buying something that may break and you need to call customer support and have it replaced, there is no substitute for an actual company with a real warehouse and a customer support line (that will actually be answered).
There are a bunch of "one-man" operations out there drop-shipping lights from China, and some of them are OK units. The issues will start when the unit breaks, has a faulty driver, fan stops etc... If they ask you to send the light back and THEN they will send you a replacement, that is an issue, they should send the replacement out immediately and allow you to return the light in the box the replacement came in--postage paid!
Unless you are prepared for the potential headaches, DO NOT buy LEDs from drop shippers. If they don't have them in stock and can have them to you in 3~5 days, they are most likely a drop-shipper (unless they just happened to sell out their entire inventory–which happens).
What's the word on the street?
Check out other people's journals, look for reviews, Google the name of the company and if possible the name of the owner of the company. T here is a whole internet full of information out there and if you don't take the 5 minutes to research the company that you are about to send $1,000 of you hard earned money to, shame on you. There is at least one company out there that is known to have reputation of poor customer support and going as far as calling the local sheriff's office on one of their customers because they weren't happy with the result of a customer service dispute (avoid any company that has threatened to put additional charges on your credit card, or that they will call LEO and report your "illegal" grow, sounds odd, but it has happened).
Read grow journals that have the lights you are interested in, when possible look for comparison grows. Beware of company's own website testimonials unless they're linked to a known grower. Check out YouTube as well for grow information, but again, be aware that some companies are posting their own videos and passing them off as satisfied customers.
Research the company. How long have they been in business, check out the whois.net to see when they registered their company site, where they're located etc...
Do you own research and make your own decision. At the end of the day you are the one that pulled the trigger and spent the money and the one that will have to live with the results if your decision was made in haste.
When you do decide to make a purchase, here are some questions you want to ask the company:
1) How long is your warranty?
2) What is your replacement procedure?
3) Are your units in stock, or do you drop-ship them from the factory?
4) How many employees do you have? (some companies claim to have in-house scientist, ask for their credentials if they are making that claim. Some one-man operations are fine, but then one person is taking, filling and shipping orders and handling customer service)
5) Ask for details on the light, number and type of chips, actual wattage, recommended core coverage and height above canopy etc..
6) When will this unit ship, and when can I expect to have a tracking number?
I am sure that you have more questions now that you've read this, that's a good thing. It means you're doing some critical thinking. Now it's time to do some homework of your own, fire up the search engines, crack a book or magazine article open and make and informed decision. If you find some information to share feel free to put it here. The only thing I ask is that you keep everything here company name free and not make specific endorsements on a manufacturer. If you want my recommendation I will send it via PM (or you can read my journals)