A completely simplified guide to buying grow lights. I'll cover the basics you need to know if you're growing seedlings and ignore all the extra information that just confuses us all.
Why ignore a bunch of grow light information? Because decision fatigue is real & as I was researching for my own replacement grow lights I JUST WANTED SOMEONE TO TELL ME WHICH LIGHTS TO BUY.
This is not a guide that has all the information on all of the lights.
I am here to make things easy for you.
Picking the right grow lights can be overwhelming, therefore I'm making this as simple possible.
If you are growing seedlings indoors, use T5 fluorescent or T5 LED lights with a colour temperature of 6,500K.
That's it. Go buy 'em. Incidentally, 6,400 is fine too. Or 6,600. Just get something above 5,000 and below 7,000.
If you like to know a bit about the whys and whats, read on.
Table of Contents
How to Pick The Right Grow Lights
Let's make this easy on everyone.
Choose T5 bulbs; they're affordable, lightweight, and very effective. They're the best choice for anyone who is growing seedlings in their basement or spare room.
What's a T5?
This is very basic information that really helps you understand lighting, yet it's a fact that often isn't explained.
With a T5 light the T refers to tubular and the 5 refers to the diameter (⅝").
Therefore a T5 light is a tubular light that is ⅝ths of an inch in diameter. They usually come in 2', 3' and 4' lengths.
Using a T8 light as an example: A T8 light is a tubular light that is 8/8ths in diameter. (1")
So T5 is code for the shape and diameter of the bulb. Nothing else.
T5 LED versus T5 Fluorescent
Now that you know that T5 only refers to the shape and diameter of the bulb I can tell you that they come in both LED and fluorescent options.
So you could buy a T5 fluorescent bulb or a T5 LED bulb. And they look pretty much the same.
So which do you pick? T5 fluorescent? Or T5 LED.
Compare 'em
- Energy efficiency: T5 LED lights are generally more energy efficient than T5 fluorescent lights, using up to 50% less energy. LED WINS.
- Longevity: T5 LED lights have a longer lifespan, lasting up to 50,000 hours compared to T5 fluorescent lights that last around 20,000 hours. LED WINS.
- Heat output: T5 LED lights produce less heat compared to T5 fluorescent lights. FLUORESCENT WINS.
(This is subjective, but when growing seedlings, I like the added heat of fluorescents on my plants BUT have experienced burning on the leaves because of it.) - Cost: T5 fluorescent lights are less expensive but over the long term, LED lights can save you money because they use less energy and won't need to be replaced as often. FLUORESCENT WINS?
- Light spectrum: Both T5 LED and T5 Fluorescent offer what you need - a colour temperature of around 6,500K. TIE.
If you want to save money in the short term - choose fluorescents
If you want to save money in the long run - choose LEDs
But really I think you should get LED lights.
Great! Now you know to:
BUY FLUORESCENT OR LED T5 bulbs
Now you only have 2 more factors to consider,
- The colour temperature of the bulbs (warm or cool).
- The physical length of the bulb.
The 2 most important things to recognize when you're buying your lights.
THE COLOUR OF THE BULBS
The colour temperature of light is measured in Kelvins. For promoting vegetative growth (leaves) the BEST light is in the range of 5,000-7,000 Kelvin with the sweet spot being 6,500K.
REMEMBER
Warm light from 3,000-4,000 Kelvin promotes flowering and fruiting.
Cool light from 5,000-7,000 promotes greenery and is perfect for seedlings
THE LENGTH OF THE ACTUAL FIXTURE
I don't mean the wavelength of the light - I mean the actual length of the bulb. Most grow lights come in lengths from 2 feet - 4 feet.
Choose the length based on how much room you have to grow.
Small space like a countertop? Use a 2 foot light.
Longer area? Use 4 ft.
Using 3' wide shelving? Use 3 ft.
Most bulbs on the market now are connectable. So you can buy 2, 2' bulbs, and in the future if you need to you can attach them together to make 1, 4' long bulb.
How Many Lights Do You Need?
This one is tricky because it depends on your setup but generally speaking I recommend using a wire rack as a setup, with 2 bulbs that run the full length of each shelf.
Like this.
So if you have 3 shelves you'd need 6 lights that are the length of the shelf. 2 for each shelf. 5 shelves, 10 lights ... and on and on. You get it.
Just zip tie the lights to the racks and you're on your way.
For super fancy people (like myself) you can also add pulleys to your lights so you can raise and lower them easily. I have 6 pair of these pulleys and I love them.
I'm smack dab in the middle of redoing my entire grow system including upgrading from fluorescent bulbs to LED, changing the technique I use for capillary mat watering, adding 2 new grow racks, and putting all my lights on pulleys.
I'm making a lot of improvements and changes but no matter what I do my basement will always & forever look like a kill room. #circa1840
FINAL TIPS
I've been using grow lights and starting my own seedlings for decades and every year I learn or try something new. So if you screw something up don't worry about it.
- LED lights should be 8-12 inches from the top of your plants, possibly more if it's a setup with very strong lights. T5 bulbs should be 5-6 inches from the tops of your plants.
- You need more room than you think to grow seedlings. Don't forget 50 tiny little seedlings are going to take up a LOT more space when they're 50 potted plants.
- You can save some money by buying 6500K "shop lights" instead of grow lights.
What's the difference between shop lights and grow lights?
Nothing.
Not really anyway as long as they have the right colour temperature(6,500 or 3000 depending on your need). The real difference between the two is price. Shop lights are cheaper.
But there's a caveat. Shop lights don't come with a reflector and your lights should have a reflector. So this option is best if you already own reflectors from past setups.
On the left is a T5 fluorescent grow light with reflector.
On the right a T5 LED shop light.
omg is this ever going to end, right? i swear to you this is the simple guide.
What I Own & Use
The exact things. Same make, colour etc.
The perfect grow setup. Shelving units are the most efficient choice for a grow room.
Pulleys make it easy (and strangely satisfying) to pull your lights up and down.
Save money by getting shop lights instead of grow lights.
Only if you already have reflectors or plan to make some though.
But what about lumens and watts and all the other bothersome stuff? Don't worry about it. T5 LED or fluorescent, at 6,500K. That's all you need to know.
Seriously. This was the SIMPLE guide. I didn't even get into PARs or ballasts or prongs.
Have a question? Go ahead and ask. But you probably just need to buy some 6,500K, T5 LED bulbs.
Wonderful and simple! Love it! Now question: the shelves (which is what I've been struggling to buy because I was actually given a grow light haha) the shelves are only 36" wide/long. But my grow light and the lights you link are 4'. So how do you fit a four foot light in a 3' shelf? Or is there a different shelf you bought? Or shorter lights you use? (Also the link to the shelves is for a 4 shelf unit but your photos show a 5 shelf unit. Wondering which is better to get? My husband wants to just get some shelves from Costco... I'm the one dragging my feet 😆
Hi Jeanette! Excellent question! I set my racks up (3 in total) in a "U" shape so the shelves each get extended by 1' on the ends. It's difficult to picture but, the result is 1' gets added to the 3' shelf, giving me 4' of room for lights. I did it this way partly because the Amazon shelves were so cheap, partly because I already owned a setup ready for 4' lights and partly because of how small my basement is. SO. For you, if you're starting from scratch and have room for 4' shelves then that's the way to go. Or the Amazon shelves with 3' long bulbs. ~ karen!
Hi Karen...this post is just what I was looking for! I've ordered everything you recommended from your links...I hope you make a million $$. I wanted two sets of pulleys but there is only one set left! I can't quite envision how to make a reflector...could I just tie the film above the lights to the bottom of the shelf?
I own a small flower farm, and start thousands of seeds every year. I don't have T5 lights, just these cheaper ones, and they work just great for me! (https://www.amazon.com/gp/product/B09P12BSYZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1) So I'm saying for everyone, if you already have something that works, or don't have the budget for fancier lights, your plants might be just fine.
One last question about seed blocks! What is your magic soil recipe for seed blocks? Or is a commercial product adequate? Saw your capillary mat lesson and seed blocker lesson, so helpful! Thank you!
I second your recommendation on those pulleys--they're great!
Thanks, for all the great information, Karen. You gave me the courage to spend some money: I clicked on the links and purchased everything, including the fans. I can't wait to get started. Last year, I cobbled together a growing station with shoe racks in a south-facing window. Thanks to you, my garden and I are getting a well-deserved upgrade. Can't tell you what your blog means to me. I've been here from the beginning and it's always the best. Happy gardening!
While we’re finding your sources, where do you get the wicking sheets ( under watering fabric?) BTW I needed a second heat mat as some seeds require 70-80 and others 60-70 degrees, and found a local Ontario (I’m in SW Ontario too) source Indoor Farmer in Waterloo! Cheaper than Amazon.ca Nice to shop locally!
This popped into my feed just when I needed it. Thanks! I've been down this road before, stopped, and am trying again in a very small way. I just can't stop myself in the dark of February. I NEED to see something grow. :)
Ahhh this post is great. I agree on all points in this post, and after growing orchids for decades now, I will tell everyone reading this: YES, do THIS. THIS is exactly what you want and it will work out great. And I'll say for other plants too. I grow plenty of prize-winning orchids and this is what I do, too.
If you're asking "But don't I need PLANT lights?" The simple answer is NO, you need LIGHTS. Light is light is light. You only need crazy specialty lights if you're really trying to get the most intense light or if you're trying to get a specific color "temperature" light to force blooms at non-blooming times of the year. Unless you are at the absolute top of your game at your plant club, you don't need complexity like that.
Lights like the above are good for most people in most cases.
One more note on fluorescents. They usually contain mercury. When they break they release that into the air. You do not want to breathe this. They are terrible for the environment, and some locations even require you dispose of them at an appropriate recycling facility. So yeah, don't buy fluorescent if you can avoid it. LED all the way, baby.
The US EPA's site suggests cleaning broken bulbs this way:
https://www.epa.gov/mercury/cleaning-broken-cfl
I just got the wrong ones in mail yesterday! I've never found this much GOOD advice in one short period and saved it on a big sheet of paper for my future gardening me.
I have bought 1 new grow light each season now for a couple of years. Which means I can never again buy the exact light that I already have, that I trust and like..
One light I have, a full spectrum LED puts out good seedlings, but it puts out more heat than I would have ever expected out of a LED fixture. Which means I am constantly having to make sure those soil blocks don't dry out. So that is one thing that one might want to ask before purchasing a new light...The light I bought this year has 2 settings, one for seedlings, another for flowering. And it doesn't put out any heat and the seedlings are doing well under it...
That sounds like a fancy light! Those setups where you can change colour and turn individual bulbs on and off are nice ~ karen!
OMG, the pulleys! Of course! I’ve been using a very cumbersome setup of chains and S-hooks. Sometimes one end will fall while I’m adjusting the other… “buy now”
I did the same thing for years, lol. Tried to "make it work" by using hooks and chains and even regular pulleys. But once I got these I was mortified I hadn't bought them sooner. ~ karen!
Hiya, longtime seed starter myself, love your setup. I still have fluorescents as chose those several years ago but will upgrade to LEDs soon. I use traps and bottom water and pest pots but plan to move to soil blocks as peat becomes unavailable. But I don’t have the Mylar. How do you use it on existing reflector lights?
Thanks to you and Philip as always for tips!
Hi Terry! I don't actually use the reflector, I should have made note of that. I suggested it for anyone who doesn't have reflectors. You can add it to the front or back of your setup to help reflect light. Or you can grab some foam core board and cover it to DIY some reflectors to hang over the top of the lights. So. There's no real need for you to get mylar if you have lights with reflectors. ~ karen!
Thank you so much for this, my life has just become way easier!
You're welcome! (I know the feeling) ~ karen!
Ok so why weren’t you there with me at Canadian tire today …I got some LED stuff.
I was just busy doing stuff. Next time! 😂 ~ karen!
How warm does the room need to be? I’d like to grow herbs, etc. in the basement which is a bit on the cool side (in Victoria). Thanks!
Hi Diane! A cooler basement is fine, but if it's really cool I'd just buy some warming mats to put under the seedling trays. With those you could grow seedlings in very cold room. ~ karen!
The fans...please give us the skinny on where to find those fans!
Found some.
AC Infinity MULTIFAN S5, Quiet Dual 80mm USB Fan, UL-Certified for Receiver DVR Playstation Xbox Computer Cabinet Cooling https://a.co/d/12CjMZh
Ha! I just linked to that. But I don't think the 80mm ones will be large enough. I'd select the 120mm size ones. :) ~ karen!
HI Carla! Aren't those fans fantastic? They're becoming easier to find. If you have a local garden centre or hydroponics store you can find small grow rack fans there. I looked into the ones on this particular grow stand and they're mini fans that are supposed to sit on top of computer equipment to keep it cool. You can get 2, 4.5" fans for $19 on Amazon US. ~ karen!
I will do you one better: OLD computer fans. Don't buy! They're free and you'd be recycling materials that would end up in a landfill. Ask your local computer nerd. If they've built more than one computer in their life I can almost guarantee they have extra fans. In my house, with TWO computer nerds, we have a literal bin of old fans. I have used them for my orchid growing for years, because orchids really really need the airflow because it's so humid in my grow areas.
Splice the wires into an old cord of a 5V phone adapters and you have an instant fan set up. They will look similar enough if you get 4 of the same size, unless you're looking for your area to look really classy. Where to get old 5v phone adapters? Ask someone with pets if they still have charging cables that are kinda shoddy because they've been chewed... haha. They will likely have some that they didn't have the heart to throw away.
On a related note I use that very wire shelf rack to hold my pots and pans. Quite sturdy and worth every penny. My ex was an avid gardener and back in the day I built a similar grow light arrangement out of 2x4s and some ply (money was tight and lumber was cheap) and Amazon wasn't yet invented.lol
Hi Randy! I was amazed at how sturdy they were. They're so good that after buying one rack, I ordered 2 more. ~ karen!
yeah hard agree with ALL these comments too. that's my plant area (not for seedlings except in March->May) and it works GREAT. Plus you can get wheels for them. AND then you can tie things/ hang stuff from the slats. Also there are HOOKS you can get for the wires. So I have my misting supplies and extra hangers and tags all contained in one movable unit.
Do the led lights fit the regular T5 fixtures or do you need an adaptor?
Hi Shirley! Good question. One I didn't have time to get into in the post lol. LED lights come two ways, with pins that will fit into your old T5 LED ballast or - with no pins like the ones I bought that don't require any ballast. When you're shopping just make sure the T5 LED light has pins and you'll be able to switch your old fluorescents out with no problem. ~ karen!
Bless you for this post!
Oh good! I'm glad it was helpful. ~ karen!