I'm using two shop light fixtures over 4 10x20 trays. They each have two fluorescent bulbs. Mine are 2,900 lumens & 6,500 kelvin. They work great for tomatoes, bell peppers, onions, zinnias & snapdragons.
Wow! This was so helpful! This will be my first experience growing seeds inside, and I knew nothing about the lighting requirements. Thank you so much for making this so easy to understand!😊
Thank you!!! I have been looking for a simple explanation for the distance between my seedlings and the light. Adding an inch for every thousand lumens… Nobody has explained this in any video! Again thank you. 🙏 🌱
Thank you for remaking this video 😊 I was watching your old video on this topic and im impressed on much you improved and grown as a video creator and as a person. You're much more confident and well focused now.
Luke. I think you could do a few more videos on lights. What is full spectrum? Why do some grow light companies advertise full spectrum grow lights but don't acknowledge lumen amount? What would be your preferences in the indoor lighting area. What about eye damage? What would you use to shield your eyes? Energy bill issues. Your explanations are the best I have seen on RUclips. I am finally "getting it".
Thank you! I watched your hardware store grow light video some time ago and didn't write anything down so I went to watch again and saw this. Thank you! I used blurple lights for micro greens but will get some different lights for this fall/winter/spring.
I'm starting Dalia seeds in doors under lights so this is very informative, didn't have a clue about lights, never heard of kelvins or lumens, watching these videos before shopping for lights, thanks for explaining everything
There are a few more issues I have had to face. My light is a 4500 lumen shop light and I have had it for years. How long should it be expected to last? Also when I first started I didn't know how long to have the light on so my plants got very spindly with 5 hours of light. I raised the time to 9 hours and the plants did well. You also should use a timer to turn the lights on and off so you don't forget the plants lighting and they get a chance to sleep. I found the light chains extremely difficult to adjust so I used empty boxes to move the plants and seed plantings close to the light for maximum efficiency. When the plants reach the lights I merely remove the boxes and they continue to grow happily. I also cover the boxes with plastic bags to keep them dry just in case there's leakage. I would love to grow year round plants for greens, for salad and radishes. I have the shelving to assemble, lumber for beds, and grow lights. I just lack the strength and energy to assemble everything. I would love to get this done and share it with you, but I'm an old guy and can barely make it up and down stairs to the basement where I want to do this project. We'll see what and if this happens. Thanks Luke for another great video. I am still very interested in the pumpkin garden final harvest, production received, and what you did with the many pumpkins I'm sure you got. May the Lord keep blessing you and yours. Love you buddy.
Thanks for a great informative video. Now time to check my lights have the right kelvin and lumens. I purchased seeds from and can't wait to start growing. First time gardener here.
I have 2 hydroponic strawberry plants that I'm growing under T5 lamps. One plant is doing really well the other one going okay but not growing as well. I was going to raise my light that is about 6" but am now rethinking that plan. Thanks for this video.
Thanks so much for the great lesson on grow lights! I had a great set up with a basic shop light fixture with two 8000K, 2700 lumen bulbs and the fixture just recently pooped out. I can't find another one but after watching your video, I found some 5000K, 3200 lumen LED lights that I think will do the trick. They are full spectrum and supposed to be made for plants.
Finally some good info on spacing - most sites and youtubers just say "it depends"! However, a trigger alert would be helpful - I got a pre-migraine aura or visual disturbance from the very bright lights you showed.
Can you do a video on the electrical costs to run your growlights based on the KWH usage. I have done for myself. Then do a comparison of electrical cost vs the food produced vs to produce seedlings.
Thank you for the great info in both of your videos about grow lights. I have seen lights advertised as "grow lights". Just wondering what is the difference between those and buying regular bulbs that you are talking about?
I have the workshop light version, how would I add lumens to that set up? I use a metal shelf rack and attach the light to the upper shelf. How do you add lumens?
Thanks for the video! We bought a tower from tower garden and on their site there is a grow light called the germinator. Have you heard of that light? I’m curious if it’s actually a great light for growing our new seedlings… thanks so much!
A ballast isn't the fan. It is a combination of starter and transformer. Make sure LED lights have a good heat sink. If they are mounted on aluminum backing then that's good. Heat will shorten the lifespan of your LED lights. A strip that has waterproof coating will not last as long because the heat cannot dissipate as well.
Excellent video! There is very little info on LED lights (I'm talking LED shop lights) for seed starting. This gives a clear description of Kelvin and Lumens. Thank you! I'm a Maryland Master Gardener and we will be having a workshop on seed starting in February. Can I have your permission to share this video with participants?
Thank you very much for the in detail explanations which really helped me out understanding my concerns with my LED tube lights. 4000K was more than enough to get my carnivores through the winter but I really struggled with my seedlings, basically needed to put the lights right in their face. Will try to get some higher Kelvin values for my next seedlings.
Should I use frosted or clear lens LEDs? The tubes I bought have a lumen rating of 3200, 200 more than the frosted tubes I was forced to get on my first purchase. Besides the extra lumens, is there any advantage of one over the other?
You have a lot of comments and I did not read through them my question is with the new LED lights that are available now. How far off the plant should they be, what is the maximum off the plant and can you actually put the seedlings in a deep box in a with foil Wrapped all the way around the inside to reflect the light. I look forward to hearing your answer. Thank you for your time and your videos. I appreciate them.
The ballast device in a florescent fixture is there to spark the gases in the tube to life, like the flint in a cigarette lighter. Once the low resistance ionized gas cloud is established inside the tube, the ballast supplies enough electrical resistance to restrict the amount of current in the tube, thus keeping it from reaching harmful levels of heat.
LEDs don't flicker by nature. They can be switched on and off which makes them great options for being controlled by PWM for power saving and dimming methods or simply operating from AC.
@MB-co6qj Agreed. I also think the cost to benefit ratio of growing brassicas using a proper light will be cost prohibitive unless they really value growing their own brassicas.
I winter sowed everything for my food and flower gardens this year, and I'll never grow inside again. It really is a cost effective, easy way to start seeds.
@@mlynnw7831 That's what I'm going to do from now on because working full-time and baby sitting plants is just too much work. Plus, I don't like leaving anything on while I'm not home.
Thank you for this!! So can you also explain the flowering part under grow lights please…?? You’ve seriously helped me understand lights in general for growing but if I were to try to grow a tomato indoors…. The flowering stage is different…. Now my mind is asking all the questions on that! 🤣🤣 Luke please help!
Flowering is different for alot of plant so it'd be hard for him to. Certain plant flower in certain conditions and times so its different for each plant. Like, heat, some only flower if you acheive certain temps or humidity, light some flower based on how much light they get. And you could have all that right and not check soil ph or nutrients right, which could keep them from flowering, also certain plant need external pollen while some can self pollinate, thing like corn or plants may flower but never produce without other pollen sources around from same but genetically different plants.
In grow light there are some that turn off spectrums seen in spring and leave more spectrums seen in fall, and vice versa. However depending on what you growing you might not want less spectrum certain thing flower in spring that dont in summer or fall and vice versa. So flowering is hard in general to talk about without the context of what your trying to flower.
Loved the solar panel analogy. I have a 6000 Lumens in lights so I know that I can go up to 10 inches away. But I have a tomato plant that wants to eat the light. How close can I let it get? 😎
The plants distance depends on the PAR produced. The closeness you can allow the plant to get depends on the heat produced by your light. Your plant knows how close it wants to be based on the 'PAR' it's receiving, but it's ignorant regarding heat, and it will burn itself.
So, in alignment with what William mentioned, it's essential to shift the focus from high lumen lights to the right spectrum for plant growth. Instead of lumens, consider searching for grow light spectrum information. Opt for a LED light that delivers around 3 micromoles per second (umol/s) per watt. This will allow you to position the light approximately 6 inches from the top of the plant. Additionally, when evaluating grow lights, pay attention to metrics like PAR (Photosynthetically Active Radiation) and PPFD (Photosynthetic Photon Flux Density). These metrics, especially PPFD measured in umol/s/m², provide insights into the light's efficiency in promoting plant growth, verse heat, 3 umol/s being in the best market. general conversion for other types of grow lights is as follows: Standard hps get .9 umol/s and standard fluorescent about 1.6 umol/s. cheap leds get as much as 2.7. The projected best umol rating for led is 5.1 with up to 3.5 in the next decade coming. So if you invest in a 3 umol/s light and it last a decade you will get your moneys worth 10x over. I still got led red/purple glow lights that keep ticking at least 8 years old. Then again i also had a few brands die at four years.
Thank you Luke. Great posting and explanation. The cost of it all ? not really worth it. Unless you grow a cash crop, the Gov't don't allow here yet. Green house? That allows me plenty early start. Love the Green House.
@migardener If I am using 8 ft 6500k 5000 lumen bulbs 40,000 lumens total) then you are saying my tomato seedlings should be 4 foot away? Won't that make the seedlings leggy?
HTG Supply sells T-5 grow lights, 20,000 lumens. See Luke’s note at the 11:00 mark of the video for the height. Everyone on RUclips quotes 6 inches. The is NOT right. I cooked my plants at this heights. Soil temps hit 100 degrees. Again, see Luke’s height recommendations.
Don't worry, your plants will tell you if the light is too close or too far away. I followed the instructions on mine and had to move it closer with certain plants.
Some good info here, but better to use a actual number of lux/lumens. Par is even better. There are lux meters you can use to measure, or you can also use your phone and then covert to par using a conversion factor. 5k light - multiplier X 0.02 4k light - multiplier 0.024 - 3.5k light multiplier 0.022 - 3k light - multiplier 0.023. I used this to grow seedlings and it worked fabulously to get stalky cucumber.
umol not lumen is what you need. As a weed grower its disappointing you talked about lumens which mean brightness alone, how many candle lights it is. And lumens has nothing to do with the usable spectrum. umol or ppfd is what you should talk about, which is the amount of usable photons for a plant to grow. There are grow lights with low lumens that put out specific spectrum they need they are generally red looking leds Mostly older led lights. Now there are white grow led lights. Grow Light Efficiency - Micromoles per Watt (µmol/W) A higher wattage doesn't always mean a higher light output. Why? Because some lights emit more µmol per Watt than others - they have a higher efficiency. This is what really drives running costs down. Since you can hit a higher light intensity on a lower wattage, you can get a greater amount of light and emit less heat. This is the main reason people switch to an LED grow light in summer. A typical HPS grow light will be around 1.6 to 1.9µmol per W. Yet many LED light hits 3.0µmol per W. That is almost twice the amount of light as some grow lights - way more bang for your buck. This is especially true of LED lights, which are known to last around 4-10 years+. Intensity - PPFD (Photosynthetic Photon Flux Density) To measure your light intensity overall, you need to look at your PPFD. It tells you the amount of light your fixture emits overall. This is really useful if you're trying to compare one grow light to another. You can measure this with a quantum meter or integrating sphere (aka Ulbricht Sphere). It'll tell you how many photons are emitted per second. This is known as the photosynthetic photon flux density (PPFD) and is measured in micromoles (µmol/s). Quantum Meter The only (slight) issue with micromoles and photons... ...is that only photons from the PAR range are counted. Photons from wavelengths lower than 400nm (e.g. UVA & UVB), and higher than 700nm (e.g. infrared & far red) aren't counted. Wavelengths outside of the PAR range have been shown to play a key role in plant health: Hormone signaling Formation of beneficial substances (e.g. essential oils & phytochemicals for defense against pests). Just make sure you check out the spectrum charts of a light you want to buy. Some growers buy supplemental CDM lights too, which are known for broadening your grow light spectrum. Though they have a wattage of 315W, our CDM lamps gives your plant types of light that other lamps can't produce. It'll transform your crop.
Chefs kiss, this comment is gold thank you. Sadly he even said at the end of the video to discourage people from learning by putting ear plugs in. I do see where he’s coming from in the aspect of people who want to keep it simple but ignorance is part of the reason we are so wasteful and not understanding of the things that matter more/most. His video where he goes to Home Depot I explained similar to what you said and I feel that’s why he said don’t listen to us. Well, he will reap what he sows. I lost respect for him at this point, because instead of encouraging people to learn he’d rather them stay ignorant. I mean what was the point in him furthering his education going to MSU? Truly sad.
I'm using two shop light fixtures over 4 10x20 trays. They each have two fluorescent bulbs. Mine are 2,900 lumens & 6,500 kelvin. They work great for tomatoes, bell peppers, onions, zinnias & snapdragons.
3:57 A ballast is not a fan. A ballast converts electricity from the wall into a usable form for the light fixture.
Wow! This was so helpful!
This will be my first experience growing seeds inside, and I knew nothing about the lighting requirements.
Thank you so much for making this so easy to understand!😊
Researching for my first grow station. THANK YOU for making this easy to digest.
Thank you!!!
I have been looking for a simple explanation for the distance between my seedlings and the light. Adding an inch for every thousand lumens… Nobody has explained this in any video!
Again thank you.
🙏 🌱
Thank you Luke for demystifying grow lights 😊 I love your explanation. You kept it simple andI truly learned a lot!
Have received my seed order from the Thanksgiving sale. Thanks. MI gardener is very efficent !
Thank you for remaking this video 😊
I was watching your old video on this topic and im impressed on much you improved and grown as a video creator and as a person. You're much more confident and well focused now.
Luke. I think you could do a few more videos on lights. What is full spectrum? Why do some grow light companies advertise full spectrum grow lights but don't acknowledge lumen amount? What would be your preferences in the indoor lighting area. What about eye damage? What would you use to shield your eyes? Energy bill issues.
Your explanations are the best I have seen on RUclips. I am finally "getting it".
Not as complicated as it has to be cracked me up! 😂😂😂 I’m sorry….love your channel! Thanks for all you do!
This explains how I’ve been using my grow lights incorrectly for YEARS! 2024 will be better. Thanks!
I started indoor seeding for the first time this year. I really struggled with lighting. Good video, with simple explanations.
Thank you! I watched your hardware store grow light video some time ago and didn't write anything down so I went to watch again and saw this. Thank you! I used blurple lights for micro greens but will get some different lights for this fall/winter/spring.
I'm starting Dalia seeds in doors under lights so this is very informative, didn't have a clue about lights, never heard of kelvins or lumens, watching these videos before shopping for lights, thanks for explaining everything
There are a few more issues I have had to face. My light is a 4500 lumen shop light and I have had it for years. How long should it be expected to last?
Also when I first started I didn't know how long to have the light on so my plants got very spindly with 5 hours of light. I raised the time to 9 hours and the plants did well.
You also should use a timer to turn the lights on and off so you don't forget the plants lighting and they get a chance to sleep.
I found the light chains extremely difficult to adjust so I used empty boxes to move the plants and seed plantings close to the light for maximum efficiency. When the plants reach the lights I merely remove the boxes and they continue to grow happily. I also cover the boxes with plastic bags to keep them dry just in case there's leakage.
I would love to grow year round plants for greens, for salad and radishes. I have the shelving to assemble, lumber for beds, and grow lights. I just lack the strength and energy to assemble everything. I would love to get this done and share it with you, but I'm an old guy and can barely make it up and down stairs to the basement where I want to do this project. We'll see what and if this happens.
Thanks Luke for another great video. I am still very interested in the pumpkin garden final harvest, production received, and what you did with the many pumpkins I'm sure you got. May the Lord keep blessing you and yours. Love you buddy.
Thanks for a great informative video. Now time to check my lights have the right kelvin and lumens. I purchased seeds from and can't wait to start growing. First time gardener here.
Great explanation and followup. Thanks
Great video, I am starting an inside grow for Seedlings, and now have the confidence to proceed.. Thanks......
I think I finally see the light on this subject..
Very illuminating❤😂😂😂
Quick question: What are the times you want your lights on and off? Thanks
I have 2 hydroponic strawberry plants that I'm growing under T5 lamps. One plant is doing really well the other one going okay but not growing as well. I was going to raise my light that is about 6" but am now rethinking that plan. Thanks for this video.
Thanks, i've been looking for good guides. I want to try starting from seed next year.
Comment on full spectrum lights please
Thank you so much for the explanation! It was very helpful.
Thanks so much for the great lesson on grow lights! I had a great set up with a basic shop light fixture with two 8000K, 2700 lumen bulbs and the fixture just recently pooped out. I can't find another one but after watching your video, I found some 5000K, 3200 lumen LED lights that I think will do the trick. They are full spectrum and supposed to be made for plants.
I love how you explain everything! You make it all easy peasy
Finally some good info on spacing - most sites and youtubers just say "it depends"! However, a trigger alert would be helpful - I got a pre-migraine aura or visual disturbance from the very bright lights you showed.
Can you do a video on the electrical costs to run your growlights based on the KWH usage. I have done for myself. Then do a comparison of electrical cost vs the food produced vs to produce seedlings.
I am growing winter chilis to cross, Jalapenio and Aji Orange under Grow Lights of course
Thank you for the great info in both of your videos about grow lights. I have seen lights advertised as "grow lights". Just wondering what is the difference between those and buying regular bulbs that you are talking about?
Alot of energy and knowledge plus good intention. Thanks😊
Thanks Luke!
Yes very helpful, Luke. Thank you 😊
I have the workshop light version, how would I add lumens to that set up? I use a metal shelf rack and attach the light to the upper shelf. How do you add lumens?
I’m not a number person so this extremely helpful. Thanks
Thanks for the video! We bought a tower from tower garden and on their site there is a grow light called the germinator. Have you heard of that light? I’m curious if it’s actually a great light for growing our new seedlings… thanks so much!
A ballast isn't the fan. It is a combination of starter and transformer.
Make sure LED lights have a good heat sink. If they are mounted on aluminum backing then that's good. Heat will shorten the lifespan of your LED lights. A strip that has waterproof coating will not last as long because the heat cannot dissipate as well.
Excellent video! There is very little info on LED lights (I'm talking LED shop lights) for seed starting. This gives a clear description of Kelvin and Lumens. Thank you! I'm a Maryland Master Gardener and we will be having a workshop on seed starting in February. Can I have your permission to share this video with participants?
Thank you. It really helped and it was fun to wat ch. Greetings from Austria.
Thank you very much for the in detail explanations which really helped me out understanding my concerns with my LED tube lights. 4000K was more than enough to get my carnivores through the winter but I really struggled with my seedlings, basically needed to put the lights right in their face. Will try to get some higher Kelvin values for my next seedlings.
Should I use frosted or clear lens LEDs? The tubes I bought have a lumen rating of 3200, 200 more than the frosted tubes I was forced to get on my first purchase. Besides the extra lumens, is there any advantage of one over the other?
You have a lot of comments and I did not read through them my question is with the new LED lights that are available now. How far off the plant should they be, what is the maximum off the plant and can you actually put the seedlings in a deep box in a with foil Wrapped all the way around the inside to reflect the light. I look forward to hearing your answer. Thank you for your time and your videos. I appreciate them.
I heard at some point that different color lights were better for pants at different phases, though I have no idea if its true.
I bought a shop light 8000 lumens with 4000 k . Probably need to double this for sprouts Right?
Thanks so much.
Sorry, I missed which LED light you chose. Would you please guide me?
Are you able to explain Lux vs Lumen? - thanks in advance!
I have a couple led grow lights that put out red and blue light/ is that okay!? it is a lot of red and blue light. last year it seemed to do okay but?
Thank you ! Very helpful as always
The ballast device in a florescent fixture is there to spark the gases in the tube to life, like the flint in a cigarette lighter.
Once the low resistance ionized gas cloud is established inside the tube, the ballast supplies enough electrical resistance to restrict the amount of current in the tube, thus keeping it from reaching harmful levels of heat.
I need a light to go in a smallish space in a closet that doesn't need heat, so which one would I get?
Do you typically leave your grow lights running 24x7 or do the plants need a dark period to rest?
They need to rest, there’s websites that will detail times ect for specific plants.
I'd max out at 18-20, because that is the longest time in nature, usually.
16-8 is regular schedule. Try to match it with your energyprices :-)
Plants tend to not be able to photosynthecize more than 18 hrs of light per day
Ac infinity grow lights and tents are great
LEDs don't flicker by nature. They can be switched on and off which makes them great options for being controlled by PWM for power saving and dimming methods or simply operating from AC.
How long should your plants stay under grow light?.
Every time I try to grow brassicas under grow lights the stems get too long. Next year, I'll try winter sowing outside.
Same here.
I suspect your have too few Lumens/Kelvin so the plants grow lanky in search of lightintensity.
@MB-co6qj Agreed. I also think the cost to benefit ratio of growing brassicas using a proper light will be cost prohibitive unless they really value growing their own brassicas.
I winter sowed everything for my food and flower gardens this year, and I'll never grow inside again. It really is a cost effective, easy way to start seeds.
@@mlynnw7831 That's what I'm going to do from now on because working full-time and baby sitting plants is just too much work. Plus, I don't like leaving anything on while I'm not home.
Thank you for this!!
So can you also explain the flowering part under grow lights please…?? You’ve seriously helped me understand lights in general for growing but if I were to try to grow a tomato indoors…. The flowering stage is different…. Now my mind is asking all the questions on that! 🤣🤣 Luke please help!
Flowering is different for alot of plant so it'd be hard for him to. Certain plant flower in certain conditions and times so its different for each plant. Like, heat, some only flower if you acheive certain temps or humidity, light some flower based on how much light they get. And you could have all that right and not check soil ph or nutrients right, which could keep them from flowering, also certain plant need external pollen while some can self pollinate, thing like corn or plants may flower but never produce without other pollen sources around from same but genetically different plants.
In grow light there are some that turn off spectrums seen in spring and leave more spectrums seen in fall, and vice versa. However depending on what you growing you might not want less spectrum certain thing flower in spring that dont in summer or fall and vice versa. So flowering is hard in general to talk about without the context of what your trying to flower.
@@orionx79 thank you.
Thank you.
Loved the solar panel analogy. I have a 6000 Lumens in lights so I know that I can go up to 10 inches away. But I have a tomato plant that wants to eat the light. How close can I let it get? 😎
The plants distance depends on the PAR produced. The closeness you can allow the plant to get depends on the heat produced by your light. Your plant knows how close it wants to be based on the 'PAR' it's receiving, but it's ignorant regarding heat, and it will burn itself.
So, in alignment with what William mentioned, it's essential to shift the focus from high lumen lights to the right spectrum for plant growth. Instead of lumens, consider searching for grow light spectrum information. Opt for a LED light that delivers around 3 micromoles per second (umol/s) per watt. This will allow you to position the light approximately 6 inches from the top of the plant. Additionally, when evaluating grow lights, pay attention to metrics like PAR (Photosynthetically Active Radiation) and PPFD (Photosynthetic Photon Flux Density). These metrics, especially PPFD measured in umol/s/m², provide insights into the light's efficiency in promoting plant growth, verse heat, 3 umol/s being in the best market. general conversion for other types of grow lights is as follows: Standard hps get .9 umol/s and standard fluorescent about 1.6 umol/s. cheap leds get as much as 2.7. The projected best umol rating for led is 5.1 with up to 3.5 in the next decade coming. So if you invest in a 3 umol/s light and it last a decade you will get your moneys worth 10x over. I still got led red/purple glow lights that keep ticking at least 8 years old. Then again i also had a few brands die at four years.
First thing to learn - protective eyewear is a must ...
I concur!!!
Thank you Luke. Great posting and explanation. The cost of it all ? not really worth it. Unless you grow a cash crop, the Gov't don't allow here yet. Green house? That allows me plenty early start. Love the Green House.
I have grow lights are have little blue and red lights together and I cannot change them..how and when do I use it? Or do I use it at all?
Another resource
BR 30 led grow light bulb
30 W PAR38 selectable spectrum led grow light bulb
Also great for limited space
I am growing self-confidence.
how far would i need to put a LED 20 watt 24in strip with 2500 lumens and 5000 K from seedlings?
The metal housing of the fixture is used to dissipate the heat from the lamps so ...
@migardener If I am using 8 ft 6500k 5000 lumen bulbs 40,000 lumens total) then you are saying my tomato seedlings should be 4 foot away? Won't that make the seedlings leggy?
Can you pls share the name brand of the 20,000 lumen grow lights you are using in your grow room in this video, or a link on Amazon? Thanks!
Check out Harbor Freight. BRAUN 10,000 Lumen, 4 Ft. Linkable Diamond Plate LED Hanging Shop Light
@@selfreder6283 thanks!
HTG Supply sells T-5 grow lights, 20,000 lumens. See Luke’s note at the 11:00 mark of the video for the height.
Everyone on RUclips quotes 6 inches. The is NOT right. I cooked my plants at this heights. Soil temps hit 100 degrees.
Again, see Luke’s height recommendations.
@@johnkirkland7465 thank you!
I still use red blue LEDs to start my cannabis..works just fine
Can you please provide a link to what you purchased? I just want to grow my veggies indoors.
Thanks so much for all your videos, I’m learning so much and I really appreciate the info!🪴
A compact fluorescent bulb has a built in ballast
Your holding a fluorescent tube the ballast is in the fixture
A fan is not a ballast
Don't forget fluorescent lights dim/degrade over time.
Don't worry, your plants will tell you if the light is too close or too far away. I followed the instructions on mine and had to move it closer with certain plants.
You must know that I am looking for some grow lights
Love the Picasso reference but bro you are a lot more like Picasso than you think... his stuff was surrealist and not to scale!
Some good info here, but better to use a actual number of lux/lumens. Par is even better. There are lux meters you can use to measure, or you can also use your phone and then covert to par using a conversion factor. 5k light - multiplier X 0.02 4k light - multiplier 0.024 - 3.5k light multiplier 0.022 - 3k light - multiplier 0.023. I used this to grow seedlings and it worked fabulously to get stalky cucumber.
Started 72 peat pods w no light plan. Rookie mistake😊
I'm still confused, mercury halide or high pressure sodium? 😅
Also, inverse square law?
THose arent compacts they are "tube" type, compacts are the twisted ones we used to have in the house
First
A "ballast is a fan"....???.... lol....
umol not lumen is what you need. As a weed grower its disappointing you talked about lumens which mean brightness alone, how many candle lights it is. And lumens has nothing to do with the usable spectrum. umol or ppfd is what you should talk about, which is the amount of usable photons for a plant to grow. There are grow lights with low lumens that put out specific spectrum they need they are generally red looking leds Mostly older led lights. Now there are white grow led lights.
Grow Light Efficiency - Micromoles per Watt (µmol/W)
A higher wattage doesn't always mean a higher light output.
Why? Because some lights emit more µmol per Watt than others - they have a higher efficiency.
This is what really drives running costs down. Since you can hit a higher light intensity on a lower wattage, you can get a greater amount of light and emit less heat. This is the main reason people switch to an LED grow light in summer.
A typical HPS grow light will be around 1.6 to 1.9µmol per W.
Yet many LED light hits 3.0µmol per W. That is almost twice the amount of light as some grow lights - way more bang for your buck. This is especially true of LED lights, which are known to last around 4-10 years+.
Intensity - PPFD (Photosynthetic Photon Flux Density)
To measure your light intensity overall, you need to look at your PPFD. It tells you the amount of light your fixture emits overall.
This is really useful if you're trying to compare one grow light to another.
You can measure this with a quantum meter or integrating sphere (aka Ulbricht Sphere).
It'll tell you how many photons are emitted per second. This is known as the photosynthetic photon flux density (PPFD) and is measured in micromoles (µmol/s).
Quantum Meter
The only (slight) issue with micromoles and photons...
...is that only photons from the PAR range are counted.
Photons from wavelengths lower than 400nm (e.g. UVA & UVB), and higher than 700nm (e.g. infrared & far red) aren't counted.
Wavelengths outside of the PAR range have been shown to play a key role in plant health:
Hormone signaling
Formation of beneficial substances (e.g. essential oils & phytochemicals for defense against pests).
Just make sure you check out the spectrum charts of a light you want to buy. Some growers buy supplemental CDM lights too, which are known for broadening your grow light spectrum. Though they have a wattage of 315W, our CDM lamps gives your plant types of light that other lamps can't produce. It'll transform your crop.
Chefs kiss, this comment is gold thank you. Sadly he even said at the end of the video to discourage people from learning by putting ear plugs in. I do see where he’s coming from in the aspect of people who want to keep it simple but ignorance is part of the reason we are so wasteful and not understanding of the things that matter more/most. His video where he goes to Home Depot I explained similar to what you said and I feel that’s why he said don’t listen to us. Well, he will reap what he sows. I lost respect for him at this point, because instead of encouraging people to learn he’d rather them stay ignorant. I mean what was the point in him furthering his education going to MSU? Truly sad.
And I didn't hear about heat with distance either. But weed growers are a lot more particular than people who grow basil.
So I just grow vegetables. How do I know what I need?
Tomato and pepper plants in particular
@@rogerrathbun444 for seed starting or completely growing them indoors? Huge difference.
@@SaturdaySoul Seed starting and for the first 8 weeks or so
You get one minute to tell me one useful thing about grow lights, oops you failed. I'm out of here.
Yes but you don't address how far APART the lights should be.
In fact none of you gardeners address this question.