Do you need 1000W to grow indoors? Not with LED Habitats Grow Lights
A lot of people believe that you need a 1000 watt artificial light to grow hemp indoors. The reality is, you can successfully grow medicinal herbs with far less wattage, saving you money on your electricity bill while growing healthier plants. So, how much wattage do you really need to grow indoors?
Let’s take a look at this short day plants-growing myth, and how you can grow indoors with eco-friendly (and wallet-friendly) LED grow lights.
Where the myth that you need 1000W to grow hemp comes from
The idea that we need 1000 watts to grow hemp comes from the days when it was common to use High Pressure Sodium (HPS) lights to grow anything indoors. At the time, HPS lights were the only decent artificial light source on the market, and a 1000 watt light was necessary for a sufficient photosynthetic light spectrum.
The main problem with HPS lights (and other high-intensity discharge / HID lights) is that they end up wasting up to 60% of the energy they consume solely on heat output. In other words, if you’re using a 1000W HPS light to grow indoors, only 400W of that energy is being used for plant growth – the other 600W is being wasted, draining money from your pocket.
Those 400W are also giving you a fairly narrow grow light spectrum, so your plants end up not getting the amount of proper light they need.
How much wattage do you need to grow indoors?
The simple answer is: it’s not really about wattage.
Wattage is a measurement of electricity consumption, and while it’s helpful to know how much wattage your grow light uses (so you can make a more economical, energy-saving choice) it actually has nothing to do with the amount of energy your plants need to grow.
Instead of looking at how much wattage a grow light uses, it’s far more important to understand the grow light spectrum, which is measured in micromoles (µmol). You need anywhere from 180 to 1300 µmol to grow plants with grow lights, depending on how light hungry your plants are. The Cannabaceae family of plants are on the higher end of the spectrum: they need 800 µmol to grow up to 85% of their natural potential, or 1300 µmol to grow to 100% of their natural potential. Kitchen herbs, salads and other leave plants on the other hand only need 180-380 µmol.
You can use a PAR meter to determine your grow light’s intensity in ?mol for light spectrum between 400-700 nanometers (nm) – in other words, for any light spectrum that’s suitable for growing plants.
Can you use too much light to grow indoors?
Yes. Much like a human sunburn, your plants can burn or bleach if you use too much light.
More wattage may mean more light output, but it also means more heat output, which can lead to burned plants. If your grow light has an output that’s higher than 1300 µmol, your plants can go into what’s called photoinhibition, when plants start spending more energy on getting rid of excess light rather than growing to their fullest potential. As a result, you’ll be left with wilted, brown leaves and dying plants.
Some growers counteract this by feeding their plants with more nutrients and introducing carbon dioxide into their grow spaces. This is a costly way to grow indoors. Not only are you introducing the costs of CO2 and added nutrients, but a 1300 µmol grow light also needs almost double the amount of energy as an 800 µmol grow light. You would also need additional cooling systems to get rid of extra heat to prevent your grow room from overheating. At the end of the day, you’re spending a lot of money only to produce 15% more yield!
What lights should I use to grow indoors instead?
With a good light spectrum, you can grow anything using much lower wattage, saving you energy and costs while yielding healthier, bigger plants. LED grow lights still aren’t widely understood among growers, but this new technology is the best way to get happier, denser plants. They use a lower wattage without sacrificing a quality light spectrum, so you can lower your LED lights right down to the plant canopy, giving them the light they need without having to stretch out. While old school HID light alternatives, like HPS and CMH technology, have a lower initial investment, they need to be replaced frequently and require expensive HVAC cooling systems. A quality LED grow light, on the other hand, can last up to 10 years – and never requires a cooling fan. The grow lights in LED Habitat’s grow light gardens use a broad spectrum of light (including red, blue, white and green lights, not only red and blue or burple lights) to help you grow the densest, greenest and healthiest medicinal plants. Our broad spectrum light engine covers 420-660nm, allowing you to grow indoors using as little as 25 watts.
Here’s a breakdown of the best LED grow lights to use, depending on what kind of output you’re looking for:
- Microgrow: If you’re a beginner and want to start on a smaller scale, you can grow weed with our LED Habitat Grow Light Garden, or our Under-cabinet LED grow light which uses just 25 watts.
- Four-plant personal grow: You’ll need light coverage for four plants of about 4’x4′. You have a couple of options:
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- Two LED Root Max Lights, which provide an average of 577 µmol each at a distance of 3″ above the plants using just 103 watts each. This is an excellent option for vegetative or green plants.
- Two LED Ditto Max Lights, which provide an average ppfd of 849 µmol each at a distance of 6″ above the plants using just 193 watts each. This is a perfect option for flowering plants.
It’s time to keep up with the times
Continuing to use 1000 watt HID lights to grow weed will only cost you money on huge energy bills and ever increasing cooling and plant nutrient costs. If you really want to grow pot in a way that’s easy and energy efficient, it’s time to make the switch to low wattage LED grow lights.
If we can offer one piece of advice, it’s this: forget about how many watts you need to grow weed. Instead, invest in LED grow lights with a quality, broad light spectrum, even and high PAR coverage, and effective ?mol output and you’ll see happier, healthier plants in no time.
Don’t just take our word for it. Join the conversation and see what LED Habitats grow light gardener users are saying on Instagram and Twitter
-Klaus Messerer
I have 1300 watts in my grow tent how much umol is that?
Hi Tommy,
There are too many unknown variables to give you an answer to your question. The only way to really know is to measure your lights performance with a PAR meter. Thank you
Klaus
I am living in an area where growing is not legal and am struggling with the lights…
I got 2 LuCio bulb:
40 w = 250 w
3600LM
6500 K
And 2 Lucio bulb
40watts= 250 watts
3600LM
3000k
If i put all the 4 together , will it work ?
And how high from the plant should i keep it
Hi Charbel,
I could not find any information on the Lucio Bulbs you reference. However, looking at the specs you provided, it does not appear they are the right grow lights for you. Wattage is a measurement of energy consumption. Is it 40w or 250w? It can not be both and there is no equal. Lumens is a measurement of brightness for Humans, 6500 kelvin is a measurement of color for humans. None of these specs should ever be used to grow plants. The measurement missing is micromoles, without this I can not know whether this setup will work or how high to hang the lights. You may want to look at our LED Under-cabinet Lights, depending on how many plants you are growing, one or two of them will work perfectly. If your space is large enough, consider our LED Root Max light or our LED Ditto Max light for best performance. All our lights ship for free! Sincerely, Klaus
I’m growing a large grow in two tents that are 20 feet long and ten feet wide and 7 feet tall. Considering each plant will need 2-4 sq feet I’m considering multiple 1000 watt LED lights, how many do you recommend based on the size of the tent ?
Hi Luke,
We would recommend 12ea of our Led Habitat Ditto Max lights for each of your grow rooms.
Can I buy just the lights if I already have a nice set up?
Hi Karyn, we have 3 hanging light fixtures available that might fit your needs. Our LED Under-cabinet is the smallest of our lights. The LED Root Max is our most popular light for seedlings, clones and all general crops. And our LED Ditto Max is our most powerful light that will give flowering plants a huge boost. Is this the info you were looking for? Best, Klaus
I’m using 2 4×4 mars hydro ts3000 in my 4×8 on max output. I’m using 2 a infinity in-line fans running out into their own charcoal filters. My best is Hugh and humidity is low. Am I putting out too much light??? If so, I can adjust the output. And how far from plants should the height of my lights be?
Hi Anthony,
You should try to get 800-1200 umol at the plant canopy. Our Led Habitat Ditto Max lights would be perfect for your setup at 6-8″ above your plants. We don’t have info or feedback on the lights you’re using. We would suggest you contact the manufacturer of your lights to get specific recommendations
Best,
Klaus.
Hi I have a 2mtr x 2mtr x 2mtr tent what can you recommend for 4-6 autos in this space.
Hi Andy, For 4-6 autos we would recommend 2 of our Ditto Max lights to start.
Best,
Klaus
Klaus. Thanks a lot for this information. As far as I can fathom you are one of the few people who actually talk about what really matters. I live in Turkey and therefore difficult/cumbersome for me to order from you but I really enjoyed it.
Reading other comments as well, most producers are focusing on wattage – which as you rightly pointed out – is a consumption unit. And at least in my researches most producers do not publish micromoles data but focus on wattage. In fact you’re lucky if you have any info on nm.
Thanks
Gaga, You are welcome! Thank you for the feedback. We have been fighting the idea that is takes watts to grow since we started LED Habitats. We recently shipped an order to Dubai, our customer used Aramax as a freight forwarding service.
Best,
Klaus
im planning on growing my plant by my window but also getting a grow light to increase the amount of flower ill get.. how many watts do i need for that
Our 200w Ditto Max light would be perfect.
what kind of light and wattage do you recommend for a veg room of approx. 35 square feet and a flower room of approx. 50 square feet
Hi Scott, Depending on plant size, we recommend one light for every 2-4 plants. You can also grow up to 200 seedlings with just one of our 100w Root Max lights.
Klaus you have some great info here! I like the quality of the information you provide and have a question, I’ve always flowered with hps and have recently been given some leds to try out. They are aglex 2000w and have leds with spectrums for both veg and flowering. However they recomend to run both sets of leds when flowering why is this? Wouldnt the flowering plants not gain a lot from the veg spectrum?
Hi Jesse, typically veg lights lean more into the blue spectrum and flower lights are more in the red spectrum. Flowering plants can also benefit from a higher micrromole output. By turning on both the veg and flower led’s on your light the plants will receive the most energy the light can give the plants for flowering. LED Habitats gives plants the best spectrum and all the light energy plants need for flowering with the Ditto Max Light, all with only one on and off button.
We’ve been trying to talk with a friend about about growing indoors with LEDs. He insists that the input wattage is what should be looked at, not the output. From what I’m reading on your page, that would pertain to Sodium lights but not to LEDs. I’m saying that a 1000w LED output/150W consumption is fine. What’s the correct answer here (for both vegetation and flowering)? Thanks!
Hi Deb, it’s not at all about watts. You need to look at the light energy in micromoles. For veg plants you should have at least 380 umols, for flowering plant the range is 800-1300umols. Our 103w Root Max light is perfect for veg plants. And our 193w Ditto Max light is perfect for flowering plants.
Best,
Klaus
hello i am trying to grow 8 randomized street cannabis seedlings (now 2 weeks old) under one of those basic LED lights from amazon that were like $16 for 12” and everyone in the comments kept saying it grew their plants.
i previously transplanted two seedlings (50% coco 50% regular soil) that i had planted in mid october — one mutated, & the second plant is still growing but so slow and is a light green color. the second plant finally reached its 3 set of leaves after 2 months, which, slow is fine, im not worried about it because it’s a trial, since this is my first time. but now i’m starting to introduce worm castings to the second plant. but i don’t have enough spectrum intensity, i assume, because the second plant is only like an inch and a half wide. the 8 seedlings fit fine under the LED light that i have now, but there isn’t enough room for the first two older ones, and i know pretty soon i’ll have to get a bigger light for the 8 seedlings. I don’t have a lot of money, so i’m trying to keep it as cheap as possible but still maintaining a good environment for them, any ideas on which (cheaper??) LED lights could be best that can help ?
Hi M,
It sounds like your plants are light starved. A $16 grow light does not provide enough light energy for plants to thrive. This translates into slow growth, weak and small plants. You would be best off to get one of our Ditto Max lights to kick your garden into high gear. A more affordable option would be our Root Max light. Both lights come with one of the best warranties on the market, are made in the USA and ship free!
Best
Klaus
HI There, I would like to get 4 plats Auto/ normal to grow in a tent of 150x150x200. What light do you recommend please?
Hi Ronald, 2 of our Ditto Max lights is the best way to go for your tent and your plant count.
Best
Klaus
Very informative article. Hoping you can share some knowledge. Last year was my 1st. indoor grow. I use a 24x48x72 grow tent and purchased an Abrislux A1000 from Amazon. I created a bunch of problems starting with the soil and struggled with a very long grow which produced a small yet nice harvest BUT not a large yield with thin, light fruit.
I have money issues[who doesn’t!] but am wondering if another of these light boards would help or hinder the girls. I have the height but thought maybe I would add the 2nd panel upon bloom?
These boards run cool and only use 100 watts of full power. So I would be adding another 100w for a total of 200w. I know there are other considerations but I’m no rocket scientist and I really don’t understand lumens & mols, etc.
I, of course, would be interested if you had a board to recommend, as well.
Thank you
Bob
Hi Bob,
It may be that the A 1000 does not put out enough micromoles, the quality of the light spectrum could also be an issue for your plants. Your best bet would be our Ditto Max light for your tent size. One of our Ditto Max lights consumes just 193w of electricity and provides 1000umol of light energy. The Ditto Max uses the highest quality Cree full spectrum Led light chips. And it comes with a 5 year warranty and free shipping.
Klaus