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LED Grow Lights - What's Important?

Posted by Logan Fulcher on

EASY!  The PAR and PPFD with 35w/ft from 420nm to 720nm & 90° - 300w (225w actually)...

       What? Knowing what to look at to determine LED quality can seem like a confusing jungle of jargon, math, and advertisement - especially for people just becoming curiousThe Best LED Light: How to Choose. about the true potential of LEDs. Nobody wants to spend a few hundred dollars only to get a plastic 'happy meal LED' and have it sizzle out in a couple weeks.  Who wants to waste their time and money?  Fortunately, as we ease into the 21st century, LED industry has evolved into a cleaner being - slashing prices, weeding out bad players, and quadrupling quality.  Here at LHGL, our goal is to make this still expanding world as easy to navigate as possible. Accompany us as we cover the most important buying points for LED grow lights...



-1- Names vs Wattage vs. Wattage?

     Names are more than they seem.  Many companies attach arbitrary numbers to the model-names of their lights, for imagination's sake, "The L-750," which becomes unintentionally misleading when we start considering the wattage with these names: "The 320 watt L-750."  Could it become any muddier?  Yes...

     We double-down on confusion when the terms LED Wattage and Actual Wattage butt heads. To illustrate this, imagine a light that contains 100 individual 3-watt LEDs, thus making the LED Wattage equal to 300 - this light can fairly be called a 300-watt LED.  However, a good diode does not pull 3-watts, as this will cause them to lose efficiency and burn out quickly (eliminating the point of LEDs altogether!)  Instead, most lights only pull a fraction of what they are able to, and this is what we at LEDHead Grow Lights refer to as 'actual wattage;'  we include actual wattage in the title of each product alongside the model name; it is also included in the SPECS section of the product description.  Regarding our example above, the 300 LED-Watt Light, may have an actual wattage of only 240 watts. 

     One of the few companies that uses 'honest' names is Black Dog - the model name of the PhytoMax series is accompanied by a number 200, 400, 600, 800, and 1000 that is (or is slightly beneath) the actual wattage... a number that should never be ignored...


-2- Actual Wattage

      When choosing an LED light, you will want roughly 30 watts of actual wattage per square foot. This number varies depending on what you read and/or who you ask, but as a rule of thumb, the low end would be 25 watts per square foot with 35w/ft squared at the high end.  To find lights to fit your wattage requirements, use our simple LED Lights by wattage selector to find the appropriate range.

-3- Secondary Optics

          Albeit an area of intense debate and pride among manufacturers and growers alike, there is zero doubt that secondary optics (or the lack thereof) play a major role in the performance of any LED.  On the negative, secondary optics, as a fact, do absorb roughly 10% of the light produced - that's light that could be reaching your plant. On the other hand, lights without optics risk scattering their light against walls, onto the floor, or emitting peripheral light at angles that lack penetrative strength - you can't grow your walls and floor.  So... the question remains, how do we choose a good lens? 

No Secondary Lens vs. Secondary Lens

       Opinion plays a major role in determining whether or not you'd like to employ an LED with secondary optics. However, growing space and optics are inextricably linked when we buy a light and should be considered: If you have a growing area larger than 12 square feet, if you are cultivating plants in a greenhouse or warehouse and overlapping light patterns are beneficial, or you are getting a light that will be within a few inches of the canopy, an LED with no optics should suit you nicely. However, if you are cultivating in a space smaller than 12 square feet, or want to ensure strong downward light penetration, an LED with lenses will be your best bet.  When considering optics, 60° to 120° angles are reasonable.  Any less than 60° is too tight for most applications, while wider than 120° will require tertiary reflection. 

     It should be noted that most constructions include secondary optics, and LHGL always includes the optics information when available. If you're in the mood for optics science, click to learn more about LED primary and secondary lenses.

     -->     LED Grow Lights without lenses include: ProMAX Grow, Black Dog

     -->     LED Grow Lights with lenses include: HydroGrow, Lighthouse Hydro, Lush Lighting, Simulight, Truth Lighting


-4- PAR (really, PPFD)

       Bad joke, it's not golf. PAR stands for Photosynthetically Active Radiation. PPFD stands for Photosynthetic Photon Flux Density.  While we could write an entire article about PAR, PPFD, and their related & equally colorful acronyms (we will next week - stay tuned,) we'll try to keep this brief and not-too-technical for now. 

     PAR is an acronym thrown around a lot in any meaningful discussion about horticulture and lighting - To be clear, it IS NOT a measurement. PAR simply describes the wavelengths of light that plants react to.  Almost every light manufacturer these days is aware of PAR and designs their lights accordingly - don't worry about it unless you're buying grow lights not specifically made for plants. PPFD, basically, is the measurement for how much PAR (light that plants want) is hitting a given area.  As a grower, you are going to want a light that has high PAR/PPFD in the area where your plant is growing. PAR/PPFD can be effected by several factors including but not limited to: the distance of the light from the area being measured, the amount of plant material in between the source and area, and the angle of lenses built into the LED as mentioned above.  You will need a light photons to get through the dense canopy to the bottom layers of growth, and provide your budding monster plant with enough photons to keep it growing and fuel its hunger.

      LEDHead always includes PAR/PPFD (and their sister measurements) in the 'specs' section of each product when that information is available. LHGL also does not carry lights that don't meet our strict PPFD threshhold limits, so there is no need to worry about getting a 'wimpy' LEDs from us.  In the near future we'll be offering FREE PAR meters with our products, so keep your eyes peeled.

-5- Spectrum

         This is why you're buying an LED, right?!  The scientifically honed frequency of light they produce is what gives you giant plants and electrically efficient lights.  Choosing the right light with the right spectrum is of the utmost importance - so, we must ask ourselves, "What are we growing?"

          If we're growing leafy and/or low-light plants like greens and herbs, we will need a lot of blue light with some red mixed in.  You can check out lights for growing vegetables by clicking this text. Some of the lights are dedicated 'veg' lights (such as the California Lightworks SolarStorm 200 - Veg Master) while others can grow plants that grow in both veg phases and flowering phases, controlled by the flick of a switch, like the below Herifi Brand AP-020.

          If we're growing fruiting/flowering plants, such as marijuana, peppers, or tomatoes, we are going to want a lot more red light.  Many of the 'veg' lights mentioned above feature 'cycle-switching' which allows them to emit light for the early stages of growth and then switch to a later more red-heavy light when need. Almost every light we carry at LEDHead is capable of growing your plants to completion.

         Some of you may ask, what about white light, UV light, IR light, and green light?  Why do we need red and blue if we can just use white?  Surely all wise questions. For those who like to be in the know, take an in depth look at the light spectrum by reading our article: Red, White, or Blue - The Spectrum War Continues. 

-6- Money Back & Warranties

            Last but not least, the kicker. You're going to want to buy a light from a company that tells it how it is. Will they stand behind their products?  Frankly, this is one of the hardest parts of buying anything.  If we had it the LEDHead way, this would be the easiest part, but not all warranties and return policies are created equal.  Don't give up though!  We've got good news!...      

           We do our best to connect our fellow LEDHeads (#LEDHead) with companies that make lights to best serve them, and by visiting our BRANDS page, you can get a quick look at the warranties and return policies of the brands we carry - they might not all be perfect, but at least you'll be armed with the knowledge and foresight to make a wise purchase. Just in case you forget, the warranty information is also included in the 'specs' section under every product.  Please take a look at our Returns Page for more specific info as well.

           Brands with that put their money where their mouths are in terms of notably long warranty and/or return periods are: BIOS (5 Years,) Black Dog (Limited Lifetime,) NextLight (5 Years,) and Truth Lighting (6 years.) 


     Well, that's all my growers - go forth and buy your lights!  May the seeds you sew grow past the heavens!  If you have any further questions, have any article requests, or just want to say something nice (or mean,) you should comment below, hit us up on twitter and Facebook, or just email me directly:

Until next time my fellow LEDHeads!  Be the Light!

 Head LED Head         

Logan Fulcher          

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