How to Select the Best Grow Light for Indoor Growing

Posted on Feb 10 2012 - 1:04am by Mike Lieberman

Michelle Moore

Not all light is the same.

Plants respond differently to different colors of light.

Light on either end of the spectrum, blue light or red light, have the greatest impact on photosynthesis.

Kinds of Light

Blue light, referred to as cool light, encourages compact bushy growth.

Red light, on the opposite end of the spectrum, triggers a hormone response which creates blooms.

Grow lights producing the orange and reddish light typically produce substantial heat, however, some lights are able to produce full spectrum light without the heat.

Grow lights come in all shapes, sizes and price ranges.

As a general rule, inexpensive lights to purchase tend to be the most expensive to operate and the least effective. While price is not necessarily an indicator of performance, many of the efficient grow lights require ballasts as well as specialized fixtures.

Image of vegetable being grown indoors under artificial light is via fortikur.com.

Check out SeedsNow.com if you’re looking to grow organic vegetable and herbs from seed.

Click here to read more about what GMOs are. It’s really easy for you to grow all kinds of vegetables, herbs, and sprouts inside.  All year long!  Invest in a grow light and you’ll be happy.

Basic Types of Grow Lights

These lights run the gamut of performance and price range.

Incandescent Lights.

The least expensive lights to purchase cost around $30. These incandescent lights work well for specific plants where the light is placed a minimum of 24” from the plant. These lights get extremely hot so they must be used with care. Spot grow bulbs, color corrected incandescent lights, install easily and are good for use with a specific plant or a small grouping of plants. Most spot incandescent bulbs last less than 1,000 hours. Some light fixtures come with a clip handle so you can put them exactly where they’re needed.

Fluorescent Grow Lights.

They are a common choice for homeowners. Fluorescent lights are reasonably energy efficient and relatively easy to install. A typical fluorescent bulb will last approximately 20,000 hours. Fluorescent light is typically on the blue end of the spectrum. Blue light encourages bushy compact growth which makes them perfect for seed starting. Blue light is also cool to the touch making it possible to place lights within just a few inches of the seedlings.

New Full-Spectrum Fluorescent Lights.

Provide the red spectrum as well to encourage blooming.

Combining the lights in a fixture makes for even, all around growth.

The next generation in fluorescent lighting includes the new T-5 lights.

These new lights have extremely high output but are energy efficient and long lasting.

The T-5 lights triple the light output of normal fluorescent lights without increasing the wattage. Plants absorb a high percentage of T-5 lighting because the fixtures function well very close to plants. High output bulbs require a high output fixture to operate, so the bulbs and normal fluorescent fixtures will not work together.

LED Lights

The newest type of grow lights use LED technology.

One major advantage to the LED lights is the small size.

LED lights are only a few inches in diameter and are easy to mount.

In some greenhouses, LED lights may be the only practical light option.

Hanging most grow lights requires a strong greenhouse structure and a place to hang the lights.

LED lights weigh a fraction of other lights and are easy to configure where needed. According to LED manufacturers, LED grow lights maximize blue and red light to provide and excellent balance for plants.

They do not have much green-yellow light. Since humans see green-yellow light best LED grow lights appear dim to our eyes. This is an exciting new technology that will be interesting to watch as it develops.

The Best Grow Light Option

Now that I’ve given you a good rundown on greenhouse lighting options, it’s also important to mention darkness.

Almost all plants benefit from a period of six hours or more of darkness.

It’s a good idea to know how much light your plants need, but unlike commercial growers, hobbyists often have a wide variety of plants so they need to take a broad approach to lighting.

Fluorescent lights offer excellent overall lighting options.

Other Considerations

If you chose to use any type of fluorescent lighting, you will need to account for plant growth.

Fluorescent lights perform best when positioned very close to plants.

As plants grow into the light, it is important to raise the fixture.

Generally only the plants touching the lights will burn, but be prepared because they grow quickly.

Adjustable hangers are a good solution. These hangers move easily allowing you to make quick adjustments.

If you’re looking for non-gmo seeds that grow well using hydroponic systems, click here.

Your Turn

Are you currently using grow lights to grow indoors? What kind? What are you growing?

Do you plan on growing indoors using grow lights?

Let me know in the comments below.

  • http://twitter.com/greenearthbazar Michelle A.

    Great lighting tips.  We want to bring our garden indoors and this will help.  We have a tiny greenhouse attached to our home which gets lots of good natural light during the year, but when the weather turns we’ll need better lighting. Thanks! ;)

  • http://www.UrbanOrganicGardener.com Mike Lieberman

    Glad you found it useful!

  • Susan

    Thank you for the very helpful post!

  • Tris

    Cool post, Mike!  The hubby and I are really interested in the LED lights right now.  We’ve already switched to LED Christmas lights for the tree and have several LED flashlights that you hand crank…no batteries!  Looks like this is the next step for our seedlings and houseplants.  Right now, I have cool blue flourescents in shop style fixtures for the houseplants and keep them on a timer.  It works ok but we have to hang on to the burnt out ones until there is a recycling event near us because you can’t just toss those in the trash.  Big no no!

  • http://www.UrbanOrganicGardener.com Mike Lieberman

    Glad you found it useful.

  • http://www.UrbanOrganicGardener.com Mike Lieberman

    Sounds like you are on your way and doing a great job!

  • http://www.facebook.com/sandra.dwan Sandra Whitlock Dwan

    I have what I think are fluorescent bulbs installed under my cabinets in my kitchen to provide extra light to the counter workspace ~ the long tube like bulbs.  Would it be OK to use those?  And could I install full-spectrum fluorescent bulbs in them?  

    I also am slowly changing my CFL’s to LED’s in the house and have some in my kitchen so would the plants benefit from them or are the LED’s used for plants a specific kind of LED?  What makes it a “grow light” vs. just a normal light bulb you might use in your home?  Thanks!

  • http://gardeningfrugal.blogspot.com/ Angela at Frugal Gardening

    Great ideas.  However, I find creating my own grow lights units very rewarding.

  • ScottfromtheBK

    I set up a grow light system last year and will definitely be using it again this year. I have a fluorescent system (with T-5s) that I found online; the fixture and bulbs were a little pricey, but I searched around and found a better deal from a lighting distributor than from any of the gardening sites.  I figured that a little more investment up front would save me in the long run.

    The system is set up in the top of a bookshelf because I don’t have much space in my NYC apartment for a dedicated seed-starting area.  I screwed some hooks into the underside of the top of the bookshelf, took out a shelf, and hung the grow light from the hooks.  I bought a cheap light timer and set the time increment to 18 hours; with the timer I don’t have to worry about remembering to turn the lights off and on (because I would definitely forget).  I also have a capillary mat that I set my seedlings on so I don’t have to worry about watering either.

    Overall, I think my lazy-man’s system works pretty well.  I’ll try to post a picture when I get some seeds up and going…

  • http://www.UrbanOrganicGardener.com Mike Lieberman

    That’s great. 

  • http://www.UrbanOrganicGardener.com Mike Lieberman

    Sounds dope. Gonna be putting some stuff together myself. Def share the pics when you get started.

  • http://www.UrbanOrganicGardener.com Mike Lieberman

    Thanks for the question Sandra. I am not a grow light specialist and have asked someone at The Greenhouse Catalog to chime in with a response.

  • Kathy

    Sandra, you should be able to replace your standard fluorescent bulbs with full-spectrum grow lights as long as you make sure they are the same size as the bulbs you currently have in your fixture (most commonly T12). If you grow under your kitchen cabinet, I recommend that you make a platform for your plants/seedlings to sit on, so the top leaves are just a few inches below the fixture. You will need to adjust the platform as the plants grow. Your home’s LED lights are designed for visual appeal (a limited spectrum of light) and not for growing. LED’s designed as grow lights have full-spectrum light with a lot of reds and blues for plant growth,  but they are not visually appealing as a house light.

  • ScottfromtheBK

    Here are pics of my setup.  Pretty self explanatory, but let me know if there are any questions.

    I planted the seeds in coir in the biodegradeable tray which sits on a capillary mat with a water reservoir below.  The coir is working out awesome – I definitely recommend it as seed-starting medium.  In this tray I have (from left to right): genevese basil, citrus basil, mini bell peppers, cilantro (the empty row was cilantro too… I wonder if I just forgot that row… d’oh!), and cherry tomatoes.

    Hit me up if you have any questions.

  • http://www.UrbanOrganicGardener.com Mike Lieberman

    Nice bro. Good isht!

  • Andre Ferchau

    I’ve worked with LEDs since they were invented (about 1975). What people don’t realize is they
    are not at all like any other light source except, and only barely like, fluorescent.
    They and fluorescents and HIDs output less than a full spectrum. So no matter what you
    read about full spectrum only exists in the incandescent bulbs and ideally the halogen bulb.
    Why?
    The Sun is what we define as full spectrum. It has ‘all the colors’ of the rainbow. No light
    but halogens (and to a limited extent any incandescent) bulb has this same full spectrum.

    OK but so what?
    Does it matter. That’s the real question.
    Only science and you, trying out different lights, including sunlight, will determine what works
    versus what’s the cost.

    I wish someone or a site would spell all this out. The truth is that I’ve never read what
    color (wavelengths) EXACTLY certain plants need.

    If you want to see why there are different colors in the Sun but they’re not in lamps
    read about it under topics like ‘light spectrum’ in wikipedia articles about the types
    of bulbs you want.
    To get a quick look see here
    http://en.wikipedia.org/wiki/File:Red-YellowGreen-Blue_LED_spectra.png
    See how 3 led bulbs don’t give you the ‘full spectrum’ but only give 3 very narrow
    colors. it’s a bit like hearing one low, one medium and one high piano key played.
    Full spectrum would be to play every key on a piano at the same time.
    HID have more colors but when we say color we mean wavelengths. That’s the key to
    the answer of the question: What do plants really need?
    If you look at a spectrum of the Sun it’s a continuous coverage from infrared (deep red and heat) through all colors and into the ultraviolet (tanning wavelengths). Does a plant need
    Infrared? Does it need ultraviolet? Does it need a specific wavelength of red or will a
    different wavelength of red work? An LED has a red color of about 652 nm which is like
    saying a piano has a key at middle C of 440 hz . Yes you must learn the terminology and thats
    the hardest part of this. the idea is simple. One color may work well while a color that is
    so close you can’t see a difference may not ‘fit’ the plant’s needs.. after all plants are
    made to work under the Sun which has all wavelengths. The only way we provide that
    is using halogen bulbs. HID are next. Then ‘full spectrum’ fluorescents which aren’t
    full spectrum at all if you ask a scientist. Then the least ‘full spectrum’ are LEDs.
    But
    LEDs are the coolest. Fluorescents are next. HID next and halogen the hottest.
    So stop.
    Think.
    LEDs the worst for ‘full spectrum’ but the coolest. that’s some bad and some good.
    Halogen are the best ‘full spectrum’ but the hottest. That’s the best light but it’s hot.
    What’s the best choice?
    I really think that a smart innovative design would be to reflect sunlight into the plant area.
    yeah. A curveball at the end.

    Take data. Try various lights. Use HID in winter when you need the heat (in the house).

    Use LED or standard T5 fluorescent in Summer (when you avoid heating the house) and get some Sun on your plants. That’s how I would approach it for maximum result for minimum cost.

    What you want is to take away the incentive for companies to lie to you. You do that by
    buying only what you need not what they want to sell.
    How many of you know what CRI is? If it’s a CRI of 85 versus 77 and the 77 is full spectrum
    you should yell ‘stink’ I smell lies. The sun has a CRI of 100. Halogen lights are CRI of 95 or more. When you have all colors then what you look at looks right in its color. Color rendition
    index = CRI. When it looks right it must have all the colors shining on it.

    How to learn:
    Write down what’s important to you.
    Study what interests you and write it down (don’t bookmark it) Write it.
    The write of this page has 20 years to her credit working with greenhouses. She’s not
    yet an expert on lighting .. unless she’s used a spectrometer and measured the
    color of light falling on plants and measured which plants grew well using colors other
    than full spectrum. Once you do that you begin to learn.

    I’ve never read that anywhere. it’s a terrible travesty that so much time and money is
    spent by the public foisted by companies selling, often, stuff they don’t themself even
    understand. A Chinese company will rebrand something and call it something and then
    someone markets it and no one has a full picture of what it is.

    You really have to do your own studies when you want to get it right.
    or play the piano

  • philly

    Have you ever used induction lighting

  • Amie

    Hello! We plan to grow indoors come frosty weather… part of our food source comes form the food t that I grow. I do can and preserve what i know how to do …..canned is good, dehydrated is good……but fresh is best. We want to start aquaponics in our garage……and use the space around the tanks as a growing in house, (all in the garage). Any suggestions on how many lights? our garage is 14X10…….
    and we open it everyday for fresh air and what not ~that the plants need. i have to self pollinate which is timely…or “time consuming’…. but IF the lights are good and don’t cost a fortune……thats the wat for our winters.
    `please advise.

  • amoja

    Help me. I have a LOT of rather gigantic houseplants, lit mainly by costly CFL’s. I have been looking to replace them with blue, red & cool white LED light bulbs. Or perhaps some LED string lights. I understand (I think) that a white LED needs to be 450 lumens, but I need to know how many lumens a blue LED bulb needs to be effective. Or a red one. I need about 30 white bulbs, 4 or 5 red ones, & maybe 8 to 10 blue ones. I think. Not a lot of $ going on here, so I’m looking for an inexpensive source. Plain, screw-into-lamp socket bulbs. Any suggestions will be much appreciated.
    Namaste’.

  • chickenscratch

    Only thing I can say is stay away from The Greenhouse Catalog I ordered some lights from them and they did not work- DOA. No refund or replacement offered or anything. They tried to claim I was using them wrong. Come on, really?

  • chickenscratch

    Just kidding,
    Seriously though, this article is riddled with cheap plugs.

  • http://sensiseeds.com/en/cannabis-seeds devideaster

    Proper lighting is the most important factor that should be considered at the time of growing any types of plant. I am really impressed by the way you have explained about best grow light options.

  • Michelle

    Hi my name is Michelle and i was trying to get my own garden started indoor. I needed a few tips on lighting

  • Michelle

    Even wanting to grow fruits and vegetables will i have to use a certain type of lighting?

  • David

    Have you tried the lights from Illumitex? They’ve got some incredible plant growth science behind their LED grow lights.

  • Aarielle Aaers

    Wow, great comment, really appreciated it. Thanks! I love Halogens. Although the bulb is more expensive, the light is most beautiful. And, we use 12V so they’re very inexpensive. : )

  • http://growace.com/ Hydroponic Lights

    Can we decorate our home easily with using grow light ???

  • iris

    In fact, for growing your plants, the lamp must be with red and blue led, and you need to know your indoor garden area, then you can chose the right lamp for your room.

  • iris

    this lamp was use to promot plants grow quick,dear friend

  • Danny

    im using t5 lights in an industrial sized hydroponics system, but do different seeds need different hights to germanate plus do they need different lux levels, please help just starting out and dont want to get it wrong

  • http://senua-hydroponics.co.uk/ Stephen Wadding

    Quality information has been shared by you. If you are bit confuse to choose which is a better grow light then read this stuff and be sure about it. I think LED lights are best grow lights.

  • Loulou

    My experience with halogen is they release a lot of heat< I have just converted to LED, need a few weeks to see how it work.

  • Tom

    Thanks for a clear explantion of grow lights it is the best and clearest i have seen and I will not have to spend a ton of money to start our seeds.

  • Rob

    Thank you for the info. I just planted some organic seeds into little cells, and currently have an incandescent light on them, but Im going to put a fluorescent light on them now that I’ve read your article. The packages say to start indoors, Im growing some chilli peppers, cayenne peppers, and two types of tomatoes, and the label says to keep them warm and under a light. Is fluorescent a good choice? Do they need sunlight? And a few hours of darkness is good for them right?

  • Puchong Vongthongdee

    May i used White LED for Grow Light ? because my pot is small and i want it light Color friendly for human eyes.

    As i know plant love blue and red. but white led are contain RGB color but they are some RGB LED also all 3 color build in 1 LED which one this the best for human eye and plant