*Watch PART 1* of this series for further context: ruclips.net/video/gHWf4Hfi3hA/видео.html _Check out my other reviews:_ *"1000" LED Grow Lights Shootout pt 1:* ruclips.net/video/g6n8VhVGKDY/видео.html *"1000" LED Grow Lights Shootout pt 2:* ruclips.net/video/WmjOSzSF-HI/видео.html *Spider Farmer SF300 / SF600:* ruclips.net/video/RXbR-hcXeQ4/видео.html *Active Grow LoPro Max 320W:* ruclips.net/video/PCaesi_M5DQ/видео.html *Maxsisun MG3000:* ruclips.net/video/Tw6-w2gybgo/видео.html This UPS power station can backup a grow light! ► ruclips.net/video/h3sUUHCEqbs/видео.html Check out my *Grow Light Cost Calculator:* ruclips.net/video/aToYhyPZMVs/видео.html _Learn more about artificial lighting and plant growth:_ ► What is PAR vs ePAR Light? ruclips.net/video/kUpEQ4kU148/видео.html ► The impact of Red or Blue light on plant growth: ruclips.net/video/sfihE4IuFuU/видео.html ► To avoid Tip Burn: ruclips.net/video/gHWf4Hfi3hA/видео.html
@@AndroidSamsung-qz9pl When plants flower when we don't want them to, we call that bolting. Annual cool season vegetables including lettuce and spinach will bolt as days grow longer in summer. Bolting usually brings on bitter flavors in the foliage as will the usually hot temperatures that come along with longer days. Hot temperatures also cause the flowers to come on more quickly as will dry soil. Some biennial vegetables bolting is induced by a cold snap during a plants normal vegetative stage. Prone to bolting include rhubarb, Chinese cabbage, and mustard greens. Some biennial vegetables, (those that normally produce only vegetative structures their first year, flower and seed their second year), may bolt during the first growing season in response to a cold spell. Most biennial vegetables, including onions, carrots, heading cabbage, have to reach a certain stage of growth before they are able to start the flowering process. But turnips are sensitive to cold as soon as they germinate. Bolting cannot be reversed once the flowering process has begun, so replace affected plants with heat-tolerant summer crops or wait until later summer to replant for a fall harvest.
I just love how you question things that may seem like they don't make sense at first and test it regardless. No question is a stupid question. I learn a ton from you.
you know, sometimes a person just plants their garden and lets it do its own thing ,but this experiment really makes you appreciate the true science involved in what we may take for granted. i really enjoyed the technical science, although i'll never remember the terms.
I would love to test this in the other way. Increase light intensity to a huge maximum (with matching intense cooling), and shorten the light cycle as much as possible, to increase periods of darkness and growth. Perhaps we could condense the day light cycle into a 3 hour window for example, allowing for more frequent dark cycles and as such quicker crop growth.
Ps. I wanted to say that your your teaching style is great. I find that you explain complex things in a very basic manner that anyone can understand. Even as a scientist by profession who understands most of these concepts, I'm not even mad at your pace. They always told me in my studies that you only truly understand something when you can make a layman understand which I think you do great. Subbed. Keep up the good work sir and keep these interesting experiments coming!
Oh, that was so useful! I'm using 24h leds and got the same picture like yours, deformed leaves and burns. I definitely knew I made something wrong, but now I'm pretty sure I understand the reason.
You should be a Professor! I learnt many concepts of lighting which i could not understand. The experiements were well designed and the resukts were explained clearly. Have you published your data? It has all the elemnents of a high impact publication.
I just started to learn about indoor growing and lighting. I have to say this is my favorite channel I've come across. Keep up the good work, and I cant wait to learn more from you.
Great experiment. I am growing lettuces with NFT system myself in Indonesia. The pH level that I always maintain for lettuces is 5.5 - 6.3. You may want to consider this pH aspect as well.
So lettuce, at least the variety you grow, is not very sensitive to light cycle! Good to know! Thank you a lot for taking so much time doing this experiment!
I’m starting a microgreen channel soon and plan to replicate your experiments! I appreciate the science behind everything you do, reminds me of my gen bio 2 class! Well done
You were So professional in your approach, I subbed right away. Thank you! It´s winter soon, and I can´t buy commercial veggies, so this is brilliant. Let´s Grow :)
When looking at growth per watt, did you consider that with the 24 hour light cycle, the distance of the light means the coverage area is greater, so you may have been able to put more plants under the light than the other two?
Exactly, or as I mentioned in my comment just use a light that offers a dimming method to reduce the power usage instead of wasting light (as spread out light has greater chance of losses even if used for more plants like you mentioned.
It gets cold but we don't get snow here, every year I appreciate the winter season more and surprise myself in what I am able to grow (although there are failures, to be sure, no luck with cauliflower). I only have one north facing window though and it's not a place I can set up an indoor garden, but I do grow on my north facing balcony in winter too.
What a good video, very useful thanks for sharing it. I think that if we use lights with less consumption (less lumens) and closer to the lettuce, we could get the same target DLI and with the same electric consumption per gram as lettuces 1 and 2 or maybe less.
In this world people who have an opinion are a dime a dozen. Those who put out the effort to find the facts are true gems. Albo Pepper... you sir are a gem! On a different note, have you ever watched my name is Earl? You could pass as his brother with that mustache. Wishing you the best Karrma for all your videos and work. Thumbs up!
Thanks! Helped me a lot to understand things further. I would love to see such tests with Basil, as I'm struggling with my indoor setup and I'm sure I'm not watering to much / less and ferts should be good, at least in my opinion compared to outdoor gardening :)
The Inverse-Square Law of light This law states that for every foot below the reflector the light should loose 75 percent of it's energy due to dispersion. So 1000 lux at 1 foot is 250 lux at 2 foot. I have taken a lux meter and find that I am only loosing 50 percent per foot. I am thinking the reflective walls are keeping the numbers up. Also, if you are have multiple lights when you just below the reflector you only get light from it. As you move down you get light from multiple lights. This applies to HPS and Metal Halide due at the side bouncing of the wall is as bring as just below it. Where LED blow all their light down.
This is really awesome and I would like more of it. Although I have to say that the cost comparison is a misleading conclusion. Instead of moving the light away from the plant, you could save energy by using a dimmer light, or increase yield by growing multiple plants.
Yes the suggestion of growing multiple plants was put forth in the 1st installment of this series: ruclips.net/video/gHWf4Hfi3hA/видео.html The lights I was using were not dimmible and I had to make due. The focus of the test is to show the relationship between PPFD levels and Light Cycle duration in calculating the photons received by plants. It explains DLI. That's the core concept.
@@Albopepper you did that and well by the way! I am 100% agreeing with 99,5% of the video ;-) I hope it's constructive criticism. I have seen the first video 👍👍
great video! It'd be really appreciated if you put a ruller in the back of each growing box, since you're using the same pots for all of them. the difference in height would be easier to differenciate between plants, and you could use that info for further analysis. It's just a detail! Greeing from Argentina!
Thanks for the 2 interesting videos. I've never had tip burn until I received an aerogarden as a gift. My kratky lettuce is fine but my aerogarden lettuce always has tio burn. I've tried over and over to experiment with same nutrients and same water and duration. The only difference is that light included on the aerogarden. So after watching your video I think my hunch is correct about the aerogarden light.
Good video. Maybe you can try applying the light intermittently. Does it affect the crops quality? And does it really save electricity? Maybe you can make (10 min on / 10 min off intervals) or maybe (1h on and 1h off intervals). Does long or short intervals matter?
I'd love to see a continuation where you get to shorter and shorter light periods with same DLI. For lettuce, I'm curious where the watt/oz maximum is.
I agree with below- as I used to be a middle school science teacher.... You should be a Professor! I learnt many concepts of lighting which i could not understand. The experiements were well designed and the resukts were explained clearly. Have you published your data? It has all the elemnents of a high impact publication.
Very interesting. And how can we calculate the right distance from the light to the plant? I mean how did you get figures 10,5 and 12,5 and 21 inches? By using PAR-meter?
Hi, like your informative content. Can you please specify the climatic conditions for lettuce to grow, ie the optimum humidity and temperature. Keep up the good work. Lots of love from Goa.
The average person isn't gonna have the fancy sensors. A test with lights at same height will be more practical for most viewers. However it's still a contribution to the community. Thanks and cheers.
Could you do a test on growing the same crop at 24/7 vs 18/6 vs 12/12 and compare root development between them. I want to see if the majority of plants root development happens during daylight rather than night.
Interesting exercise. What I don't understand is why people choose to move the light over dimming. Is it a grow light limitation? Moving the light keeps the electricity consumption the same, while dimming it should reduce it, right? Thanks!
Correct, some lights aren't dimmable, especially the ones from a few years back. Also when you raise lights, you can cover more area and thus you can grow more plants. But I agree, dimming is a great option!
There are two sets of equations. None of these divide by 16 though. I selected 16 as the target DLI and decided to achieve that amount of light exposure for all plants. So when using a 24 hour light cycle, the PPFD needs to be 185 if I'm shooting for a DLI of 16. This was determined dividing my selected DLI (16) by 0.0864. So let's say you're growing a medicinal crop and your target DLI is 40. Then you would divide 40 by 0.0864 and that would be the required PPFD (if using a 24 hr light cycle). For a 12 hr light cycle you would divide 40 by 0.0432 which is 925.9. So for that project, the grower would be trying to cover the plant canopy with 926 PPFD of light.
i key thought , i've watched numerous videos and one thing no one seems to pay attention to point out either is the light spectrum versus plant growth of long or short day cycle plant, , as an example a long day plant with have a higher exposure to blue and greens in the 460 to 560 Nm wave length during day where as morning and evening light has a higher level of of 600 to 750 and higher IR spectrum. so all gathered this would also affect over all plant characteristics of growth determined on actual light make up for long or short day cycle plants and neutral cycle so as you go into long day plant the higher photo flux increase and slightly less red spectrum looks to be the curve. there have been studies done for solar cells that actually break down the light spectrum for full day versus time of time. so we know certain plants prefer a set time of year for growth both due to light and temperatures, we know nature doesn't always duplicate the ideal condition but we try as growers so maybe we need to look at those spectrum and intensities not just as a broad band but as a cycle so we need to look at it on an hour buy hour cycle also. as example what is the intensity of the light at 6am and its light spectrum versus what is it at 10am noon 2pm 4pm ...... all thing that will vary with a short day versus long day cycle plant. oh yes and one additional note light spectrum analysis done by labs to test for solar cell efficiency ( 300 to 1000nm tested spectrum) showed a fair spike at 410nm and extreme spike at the 740 to 760 nm light ( this is based off a full day sunrise to sunset recorded data ) and the spectrum between almost a dead flat level within the band from 410 to 740 nm
did you consider moving the light bulb upwards as the plant grows to maintain the distance and therefore amount of photons received? I mean since you did your calculations at the beginning to set the hight accordingly, but hight - distance, was not constant during the test. Maybe it would reduce the burn marks.
Great science lesson. I'm really impressed! I already have a DIY aquaponics system and I'm trying to mimic your setup #3 (24hr). Is it a good Idea to add a diffuser on LED white lights instead of bringing it up? Just like an ordinary LED bulb with white plastic that covers it to diffuse. I have limited space and I can no longer move it up. Thank you!
Greate video. I'm so sorry, but could you tell me how did you get those values(0.0864, 0.0576, 0.0432)? Was it with a PAR sensor? Answer: The 0.0864 factor is the total number of seconds in a day divided by 1,000,000.
Thanks for watching Julio! This resource is a definitive reference for DLI: www.extension.purdue.edu/extmedia/ho/ho-238-w.pdf I have a PAR sensor (Quantum Light Sensor) that I use to measure my PPFD.
I am using cheap shop leds to grow both microgreens and plants that I am going to transplant to the garden when at proper height. Can you tell me if the CRI of the light matters? I think I have the worse at 85 CRI. Thank you so much and love your videos!
Thanks for the great video and test. Can you please direct me to what the composition of your grow buckets are? How are you watering these and what nutrients does it need as well?
awesome, i just finally started using a grow light, i got fed up with the weather...this is exciting, first off..the led full spectrum is just a beautiful light, it makes me feel better just being in the light, haha, just feels natural, maybe I have SAD..I don't know this all makes perfect sense, I think leaving the lower intensity light on 24/7 at a greater distance, which allows for more plants to receive it, should be best, for what I'm trying at least, you proved that 12hr is ultimately the overall most sensible way to grow but I'm going to experiment first, honestly I'm more worried about constantly powering on/off the grow bulbs, should I not be?
A leading cause of tip burn is calcium deficiency caused by low transpiration in the leaves so that the plant can't pull enough calcium to the leaf tips... I have virtually eliminated tip burn in my setup by just putting a small fan to create airflow around my lettuce to increase transpiration. I wonder if the growth differences would have been more dramatic without the tip burn.
I realize that this is a very old video at this point, but a quick question about your setup. Did you calculate the distance to achieve the PPFD for each plant, or did you actually use a meter? I ask because if you were relying on just the math, your setup could have resulted in an actual PPFD at the canopy that significantly deviated from the theoretical due to your use of reflective enclosures. As I am sure you are aware, it doesn't matter how far away a light source is if you can manage to somehow get all the photons to still hit the canopy, be it through the use of beam angle or some other method. Yes, you will likely lose at least 10% of your photons each time they bounce off the walls of your tinfoil wall reflectors, but having those reflectors could increase your square root law-derived PPFD by a significant amount. Additionally, the 3rd experiment is going to see a larger proportional drop off in delivered photons than between the first and second. The first 2 have the fixture entirely within the enclosure but the 3rd is well outside the enclosure. As the light fixture has a beam angle under 180 degrees, far more of the emitted photons will hit a wall and bounce down to the canopy in positions 1 and 2 than in position 3, with at least some proportion of the photons from position 3 spilling outside of the grow chamber entirely. of course, all of this would be a moot point if you've used a light meter, but I never saw any reference to that in the video. I enjoy your videos, and the knowledge is on point, I'm just concerned your results may be skewed.
Hi, what was the starting pH and EC of your experiment ? Also, what nutrients did you use? Thanks so much for sharing this info. Also, have you done any experiments w shorter light cycles? 5 min on, 5 min off vs 5 min on 2 min off, etc ?
Could you do a test with all the lights at the same, Optimum height, but use a Dimmable LED for Longer day but same kW? It would be useful for growers to see which result for economic action!
Currently running in veg at about 415ppfd auto flower/ 20 hr. I believe that’s about 30DLI. My question is is that where I should be and where should ppfd and DLI be at during flowering?
increased light hours also increases temperature. Heat could be an important factor in an enclosed grow tent for example when dealing with a cool temperature crop
I recently made an indoor growing setup. We have some normal spectrum lights and some red/blue flowering lights. I put all the lights on our grow shelf thinking the flowering lights wouldn't really make a difference... but MY OH MY I was wrong. Anything near the flowering light flowered/bolted within like 2 days.
How much nutrient solution did each plant use and what was the EC/ppm levels I think is an important factor cause the one on the 24hour cycle may have tip burn due to drinking more water causing the nutrient levels to raise
Interesting DLI experiment, but my takeaway in this video is, DLI this, DLI that... why not think outside the box of "daily"? Why confine the photo period to a 24 hour cycle? Am I wrong to think that DLI can be eliminated in a controlled environment? There are infinite cycle timers that can be used instead of regular 24 hour outlet timers. Why not make it a photo period per cycle, and not per day? Or why not calculate how much total light the lettuce needs from seedling to harvest and ratio it together with dark periods in order to avoid tip burn? If you ever do another experiment, can you do one that tests for different ratio light and dark cycle duration with setup number 1? Something like 12/6 (12hrs light, 6hrs dark), or 16/2(I heard this one works good), or 8/2(short cycles = more cycles from seed to harvest in less time). Thanks
![Noob To Max With DRAGON REWORK In Blox Fruits [FULL MOVIE]](http://i.ytimg.com/vi/LnBMOinoOvA/mqdefault.jpg)
*Watch PART 1* of this series for further context:
ruclips.net/video/gHWf4Hfi3hA/видео.html
_Check out my other reviews:_
*"1000" LED Grow Lights Shootout pt 1:* ruclips.net/video/g6n8VhVGKDY/видео.html
*"1000" LED Grow Lights Shootout pt 2:* ruclips.net/video/WmjOSzSF-HI/видео.html
*Spider Farmer SF300 / SF600:* ruclips.net/video/RXbR-hcXeQ4/видео.html
*Active Grow LoPro Max 320W:* ruclips.net/video/PCaesi_M5DQ/видео.html
*Maxsisun MG3000:* ruclips.net/video/Tw6-w2gybgo/видео.html
This UPS power station can backup a grow light!
► ruclips.net/video/h3sUUHCEqbs/видео.html
Check out my *Grow Light Cost Calculator:* ruclips.net/video/aToYhyPZMVs/видео.html
_Learn more about artificial lighting and plant growth:_
► What is PAR vs ePAR Light? ruclips.net/video/kUpEQ4kU148/видео.html
► The impact of Red or Blue light on plant growth: ruclips.net/video/sfihE4IuFuU/видео.html
► To avoid Tip Burn: ruclips.net/video/gHWf4Hfi3hA/видео.html
Excellent!!!
it looks hard to do but hate the bugs outside
What is bolting?
@@AndroidSamsung-qz9pl When plants flower when we don't want them to, we call that bolting.
Annual cool season vegetables including lettuce and spinach will bolt as days grow longer in summer. Bolting usually brings on bitter flavors in the foliage as will the usually hot temperatures that come along with longer days. Hot temperatures also cause the flowers to come on more quickly as will dry soil. Some biennial vegetables bolting is induced by a cold snap during a plants normal vegetative stage. Prone to bolting include rhubarb, Chinese cabbage, and mustard greens.
Some biennial vegetables, (those that normally produce only vegetative structures their first year, flower and seed their second year), may bolt during the first growing season in response to a cold spell. Most biennial vegetables, including onions, carrots, heading cabbage, have to reach a certain stage of growth before they are able to start the flowering process. But turnips are sensitive to cold as soon as they germinate.
Bolting cannot be reversed once the flowering process has begun, so replace affected plants with heat-tolerant summer crops or wait until later summer to replant for a fall harvest.
@@Albopepper Wow. Thanks for the though reply! :)
More power to you.
I just love how you question things that may seem like they don't make sense at first and test it regardless. No question is a stupid question. I learn a ton from you.
you know, sometimes a person just plants their garden and lets it do its own thing ,but this experiment really makes you appreciate the true science involved in what we may take for granted. i really enjoyed the technical science, although i'll never remember the terms.
Thank-you for your kind words! The videos are here, so you always have this resource available to you!!! xD
I would love to test this in the other way. Increase light intensity to a huge maximum (with matching intense cooling), and shorten the light cycle as much as possible, to increase periods of darkness and growth.
Perhaps we could condense the day light cycle into a 3 hour window for example, allowing for more frequent dark cycles and as such quicker crop growth.
You should test it out and share your results!
Ps. I wanted to say that your your teaching style is great. I find that you explain complex things in a very basic manner that anyone can understand. Even as a scientist by profession who understands most of these concepts, I'm not even mad at your pace. They always told me in my studies that you only truly understand something when you can make a layman understand which I think you do great. Subbed. Keep up the good work sir and keep these interesting experiments coming!
Oh, that was so useful! I'm using 24h leds and got the same picture like yours, deformed leaves and burns. I definitely knew I made something wrong, but now I'm pretty sure I understand the reason.
Another great experiment that very simply explains a complex theory. Thanks.
Thanks so much for watching! :-)
You should be a Professor! I learnt many concepts of lighting which i could not understand. The experiements were well designed and the resukts were explained clearly. Have you published your data? It has all the elemnents of a high impact publication.
totally different light set ups with very similar results. thanks for the science lesson!!!
Thanks Kramer! This was the most scientific method I could come up with to demonstrate DLI in practical terms. :-)
Very much enjoying your process.
Just getting started in indoor gardening and until now, haven't found anything this data driven. Thank you!
I just started to learn about indoor growing and lighting. I have to say this is my favorite channel I've come across. Keep up the good work, and I cant wait to learn more from you.
Great experiment. I am growing lettuces with NFT system myself in Indonesia. The pH level that I always maintain for lettuces is 5.5 - 6.3. You may want to consider this pH aspect as well.
I haven't even watch the first video to the end but a fan already
So lettuce, at least the variety you grow, is not very sensitive to light cycle! Good to know! Thank you a lot for taking so much time doing this experiment!
Thanks for taking time to watch!
Thanks! You provide important information! These experiments should be repeat by some national labs!
I’m starting a microgreen channel soon and plan to replicate your experiments! I appreciate the science behind everything you do, reminds me of my gen bio 2 class! Well done
Good video.
I asked my self about that for a while already, nice to see your experiment results.
Thanks
Thanks, I appreciate your support! :-D
Excellent presentation of all the information!! And really well thought out experiment. Very much enjoying these.
Thanks Nigel!
Wow, he just came up with a new variable that was hided out of sight all this time... amazing!
You were So professional in your approach, I subbed right away. Thank you! It´s winter soon, and I can´t buy commercial veggies, so this is brilliant. Let´s Grow :)
Glad you did this comparison. I sure don’t put in the time/effort to find it out for myself
When looking at growth per watt, did you consider that with the 24 hour light cycle, the distance of the light means the coverage area is greater, so you may have been able to put more plants under the light than the other two?
Exactly, or as I mentioned in my comment just use a light that offers a dimming method to reduce the power usage instead of wasting light (as spread out light has greater chance of losses even if used for more plants like you mentioned.
I found that lettuce tip burn is greatly reduced on indoor plants by growing them in half-strength nutrients.
always, or introduce gap weeks.
Very interesting experiment (ofc accounting for the limitations of the case)! Keep it up!
Thanks for your support! :-D
Thanks a lot for explaining the complex concepts with such clarity. It will surely help my plants grow better.
Thanks for watching Nisarg! I appreciate your positive feedback. :-)
I love these experiments! Thank you. During the winter I am an avid indoor grower and this info is so helpful. :)
It gets cold but we don't get snow here, every year I appreciate the winter season more and surprise myself in what I am able to grow (although there are failures, to be sure, no luck with cauliflower).
I only have one north facing window though and it's not a place I can set up an indoor garden, but I do grow on my north facing balcony in winter too.
Same here, I absolutely love Albo's experiments!
xD Thank-you for your support!
Thanks Punky! I'm glad that this info was helpful. :D
Grub's Garden It sounds like you are having success despite having some limitation. :) Very cool!
Your experiments are always appreciated so much, sharing knowledge like this is extremely valuable. Ty so much for what you do.
Great experiment, thank you for creating informative and entertaining content to share with all of us - awesome work!
Thank-you Hobes! I appreciate it. :)
What a good video, very useful thanks for sharing it. I think that if we use lights with less consumption (less lumens) and closer to the lettuce, we could get the same target DLI and with the same electric consumption per gram as lettuces 1 and 2 or maybe less.
Thanks Max. Any little bit of extra efficiency is worth it! :)
In this world people who have an opinion are a dime a dozen. Those who put out the effort to find the facts are true gems. Albo Pepper... you sir are a gem! On a different note, have you ever watched my name is Earl? You could pass as his brother with that mustache. Wishing you the best Karrma for all your videos and work. Thumbs up!
That was very informative mate. Nice and straight forward.
Lovely channel ! All you need to know about plant grow lighting, explained cristal clear 👍 Albo!
I love how you are bringing science into your videos. It would be awesome if you could have triplicates of each treatment :D
Such a cool experiment! All the sort of things I'd love to try. Thanks for sharing.
-Hank
Thanks Hank! I appreciate your support. :-)
Admit it, your real name is SUPER MARIO....ISNT IT ;)
It'sa me!
*i knew it!*
Great video, sir. Thank you very much. Greatings from Argentina.
Thank you for serious and academic content, and for using PPFD and DLI!
You're videos are awesome, bro.
Keep it up. Quality content. Cheers.
Thanks! Helped me a lot to understand things further. I would love to see such tests with Basil, as I'm struggling with my indoor setup and I'm sure I'm not watering to much / less and ferts should be good, at least in my opinion compared to outdoor gardening :)
Very insightful, the only factor is missing is the humidity.
The Inverse-Square Law of light
This law states that for every foot below the reflector the light should loose 75 percent of it's energy due to dispersion. So 1000 lux at 1 foot is 250 lux at 2 foot. I have taken a lux meter and find that I am only loosing 50 percent per foot. I am thinking the reflective walls are keeping the numbers up. Also, if you are have multiple lights when you just below the reflector you only get light from it. As you move down you get light from multiple lights. This applies to HPS and Metal Halide due at the side bouncing of the wall is as bring as just below it. Where LED blow all their light down.
I use read a study about this , crazy your experiment matches the test
elo do u still remember the study name?
Great information! Love the video!
Found a small typo on 7:14 with the slide title
This is really awesome and I would like more of it. Although I have to say that the cost comparison is a misleading conclusion. Instead of moving the light away from the plant, you could save energy by using a dimmer light, or increase yield by growing multiple plants.
Yes the suggestion of growing multiple plants was put forth in the 1st installment of this series: ruclips.net/video/gHWf4Hfi3hA/видео.html The lights I was using were not dimmible and I had to make due. The focus of the test is to show the relationship between PPFD levels and Light Cycle duration in calculating the photons received by plants. It explains DLI. That's the core concept.
@@Albopepper you did that and well by the way! I am 100% agreeing with 99,5% of the video ;-)
I hope it's constructive criticism. I have seen the first video 👍👍
great video! It'd be really appreciated if you put a ruller in the back of each growing box, since you're using the same pots for all of them. the difference in height would be easier to differenciate between plants, and you could use that info for further analysis. It's just a detail! Greeing from Argentina!
Thanks for the 2 interesting videos. I've never had tip burn until I received an aerogarden as a gift. My kratky lettuce is fine but my aerogarden lettuce always has tio burn. I've tried over and over to experiment with same nutrients and same water and duration. The only difference is that light included on the aerogarden. So after watching your video I think my hunch is correct about the aerogarden light.
Just found your channel but im hooked..... thank you from.the UK !
Can anyone tell me what he says at 6:44? Some signs of tempering, was it? What does that mean for a plant?
you are the best mate! keep it going!
Exactly what i was searching for. Thanks
Good video. Maybe you can try applying the light intermittently. Does it affect the crops quality? And does it really save electricity? Maybe you can make (10 min on / 10 min off intervals) or maybe (1h on and 1h off intervals). Does long or short intervals matter?
this was quite an interesting study. I'd like to see it replicated on a larger scale.
So would I Mr Gracian. Hmm... looks like you have a busy Winter ahead of you! Let me know how your test turns out! ;-P
Great information. I also experimented with 12 varities of lettuce. Tom Thumb suffered tip burn.
This was a glorious experiment
I'd love to see a continuation where you get to shorter and shorter light periods with same DLI. For lettuce, I'm curious where the watt/oz maximum is.
You always have exactly what I'm looking for... Thanks
I'm glad I can help Chris. Thanks!
Great video man!
DLI wonderfully simple explained, new sub
Cool! Welcome to my channel!!! xD
I agree with below- as I used to be a middle school science teacher.... You should be a Professor! I learnt many concepts of lighting which i could not understand. The experiements were well designed and the resukts were explained clearly. Have you published your data? It has all the elemnents of a high impact publication.
Thanks Devin! I greatly appreciate your positive feedback. :-)
Awesomeness work, dude! You're the best! You're considered everything! Thanks much!
Thanks so much for watching Andrej!
Very interesting. And how can we calculate the right distance from the light to the plant? I mean how did you get figures 10,5 and 12,5 and 21 inches?
By using PAR-meter?
Great experiment guys 🤗
Super awesome video. Helpful for understanding my aquarium lighting a bit better too
Hi, like your informative content. Can you please specify the climatic conditions for lettuce to grow, ie the optimum humidity and temperature. Keep up the good work. Lots of love from Goa.
Hi Clinton. I would recommend checking out this resource from Cornell: www.cornellcea.com/attachments/Cornell%20CEA%20Lettuce%20Handbook%20.pdf
Interesting, Matanuska produce in Alaska is huge, 18-22 hours of daylight.
Good point! Thanks for watching. :-D
Awesome Test! Thank you for doing this.
this was awesome love these vids bro!
Thanks man!!! :-D
The average person isn't gonna have the fancy sensors. A test with lights at same height will be more practical for most viewers. However it's still a contribution to the community. Thanks and cheers.
I dont know what you just said but I enjoyed it 😂😂😂
Very informative video as usual. Thank you very much.
Could you do a test on growing the same crop at 24/7 vs 18/6 vs 12/12 and compare root development between them. I want to see if the majority of plants root development happens during daylight rather than night.
Great Experiment Bro !
Thanks man!
Interesting exercise. What I don't understand is why people choose to move the light over dimming. Is it a grow light limitation? Moving the light keeps the electricity consumption the same, while dimming it should reduce it, right? Thanks!
Correct, some lights aren't dimmable, especially the ones from a few years back. Also when you raise lights, you can cover more area and thus you can grow more plants. But I agree, dimming is a great option!
why do you divide by 16 for DLI in all your PPFD calculations? (3:38)
There are two sets of equations. None of these divide by 16 though. I selected 16 as the target DLI and decided to achieve that amount of light exposure for all plants. So when using a 24 hour light cycle, the PPFD needs to be 185 if I'm shooting for a DLI of 16. This was determined dividing my selected DLI (16) by 0.0864.
So let's say you're growing a medicinal crop and your target DLI is 40. Then you would divide 40 by 0.0864 and that would be the required PPFD (if using a 24 hr light cycle). For a 12 hr light cycle you would divide 40 by 0.0432 which is 925.9. So for that project, the grower would be trying to cover the plant canopy with 926 PPFD of light.
i key thought , i've watched numerous videos and one thing no one seems to pay attention to point out either is the light spectrum versus plant growth of long or short day cycle plant, , as an example a long day plant with have a higher exposure to blue and greens in the 460 to 560 Nm wave length during day where as morning and evening light has a higher level of of 600 to 750 and higher IR spectrum. so all gathered this would also affect over all plant characteristics of growth determined on actual light make up for long or short day cycle plants and neutral cycle
so as you go into long day plant the higher photo flux increase and slightly less red spectrum looks to be the curve. there have been studies done for solar cells that actually break down the light spectrum for full day versus time of time. so we know certain plants prefer a set time of year for growth both due to light and temperatures, we know nature doesn't always duplicate the ideal condition but we try as growers so maybe we need to look at those spectrum and intensities not just as a broad band but as a cycle so we need to look at it on an hour buy hour cycle also. as example what is the intensity of the light at 6am and its light spectrum versus what is it at 10am noon 2pm 4pm ...... all thing that will vary with a short day versus long day cycle plant. oh yes and one additional note light spectrum analysis done by labs to test for solar cell efficiency ( 300 to 1000nm tested spectrum) showed a fair spike at 410nm and extreme spike at the 740 to 760 nm light ( this is based off a full day sunrise to sunset recorded data ) and the spectrum between almost a dead flat level within the band from 410 to 740 nm
Cool experiment, I may dial mine back a bit. More is not always better.
great video..it's so informative..well done
Thanks for watching and visiting my channel! xD
Thank you, my lettuces are growing very fast and I have tipburn. I will try reducing my light cycle.
did you consider moving the light bulb upwards as the plant grows to maintain the distance and therefore amount of photons received? I mean since you did your calculations at the beginning to set the hight accordingly, but hight - distance, was not constant during the test. Maybe it would reduce the burn marks.
Great science lesson. I'm really impressed!
I already have a DIY aquaponics system and I'm trying to mimic your setup #3 (24hr).
Is it a good Idea to add a diffuser on LED white lights instead of bringing it up? Just like an ordinary LED bulb with white plastic that covers it to diffuse.
I have limited space and I can no longer move it up. Thank you!
Great experiment.
There appears to be some additional light exposure on the plants due to short walls. Could this influence the results?
Greate video.
I'm so sorry, but could you tell me how did you get those values(0.0864, 0.0576, 0.0432)?
Was it with a PAR sensor? Answer: The 0.0864 factor is the total number of seconds in a day divided by 1,000,000.
Thanks for watching Julio! This resource is a definitive reference for DLI: www.extension.purdue.edu/extmedia/ho/ho-238-w.pdf I have a PAR sensor (Quantum Light Sensor) that I use to measure my PPFD.
AlboPepper - Drought Proof Urban Gardening Thank you.
I am using cheap shop leds to grow both microgreens and plants that I am going to transplant to the garden when at proper height. Can you tell me if the CRI of the light matters? I think I have the worse at 85 CRI. Thank you so much and love your videos!
This was amazing. Thanks.
Thanks for watching Scott!
Thanks for the great video and test. Can you please direct me to what the composition of your grow buckets are? How are you watering these and what nutrients does it need as well?
Thanks bro, love these experiments!
Thanks for watching MTech! I appreciate your support on my channel! :-)
awesome, i just finally started using a grow light, i got fed up with the weather...this is exciting, first off..the led full spectrum is just a beautiful light, it makes me feel better just being in the light, haha, just feels natural, maybe I have SAD..I don't know
this all makes perfect sense, I think leaving the lower intensity light on 24/7 at a greater distance, which allows for more plants to receive it, should be best, for what I'm trying at least, you proved that 12hr is ultimately the overall most sensible way to grow but I'm going to experiment first, honestly I'm more worried about constantly powering on/off the grow bulbs, should I not be?
this video would be awesome if you have a time lapse video of this experiment
Thank you sir your content soo helpfull until this day ❤
Thanks so much for this video!
Thanks for watching Candace. I appreciate your support on my channel! :)
A leading cause of tip burn is calcium deficiency caused by low transpiration in the leaves so that the plant can't pull enough calcium to the leaf tips... I have virtually eliminated tip burn in my setup by just putting a small fan to create airflow around my lettuce to increase transpiration.
I wonder if the growth differences would have been more dramatic without the tip burn.
I realize that this is a very old video at this point, but a quick question about your setup.
Did you calculate the distance to achieve the PPFD for each plant, or did you actually use a meter?
I ask because if you were relying on just the math, your setup could have resulted in an actual PPFD at the canopy that significantly deviated from the theoretical due to your use of reflective enclosures.
As I am sure you are aware, it doesn't matter how far away a light source is if you can manage to somehow get all the photons to still hit the canopy, be it through the use of beam angle or some other method. Yes, you will likely lose at least 10% of your photons each time they bounce off the walls of your tinfoil wall reflectors, but having those reflectors could increase your square root law-derived PPFD by a significant amount.
Additionally, the 3rd experiment is going to see a larger proportional drop off in delivered photons than between the first and second.
The first 2 have the fixture entirely within the enclosure but the 3rd is well outside the enclosure.
As the light fixture has a beam angle under 180 degrees, far more of the emitted photons will hit a wall and bounce down to the canopy in positions 1 and 2 than in position 3, with at least some proportion of the photons from position 3 spilling outside of the grow chamber entirely.
of course, all of this would be a moot point if you've used a light meter, but I never saw any reference to that in the video.
I enjoy your videos, and the knowledge is on point, I'm just concerned your results may be skewed.
Hi, what was the starting pH and EC of your experiment ? Also, what nutrients did you use? Thanks so much for sharing this info. Also, have you done any experiments w shorter light cycles? 5 min on, 5 min off vs 5 min on 2 min off, etc ?
excelente video amigo, ayudas a sacar de dudas sobre periodo de alimentacion de la planta, thanks
Gracias! :-D
Could you do a test with all the lights at the same, Optimum height, but use a Dimmable LED for Longer day but same kW?
It would be useful for growers to see which result for economic action!
Currently running in veg at about 415ppfd auto flower/ 20 hr. I believe that’s about 30DLI. My question is is that where I should be and where should ppfd and DLI be at during flowering?
I don,t know any body that has a lettuce shirt. You could be the new and improved Mr. Green Jeans.
increased light hours also increases temperature. Heat could be an important factor in an enclosed grow tent for example when dealing with a cool temperature crop
I recently made an indoor growing setup. We have some normal spectrum lights and some red/blue flowering lights. I put all the lights on our grow shelf thinking the flowering lights wouldn't really make a difference... but MY OH MY I was wrong. Anything near the flowering light flowered/bolted within like 2 days.
How much nutrient solution did each plant use and what was the EC/ppm levels I think is an important factor cause the one on the 24hour cycle may have tip burn due to drinking more water causing the nutrient levels to raise
Interesting DLI experiment, but my takeaway in this video is, DLI this, DLI that... why not think outside the box of "daily"?
Why confine the photo period to a 24 hour cycle? Am I wrong to think that DLI can be eliminated in a controlled environment?
There are infinite cycle timers that can be used instead of regular 24 hour outlet timers.
Why not make it a photo period per cycle, and not per day?
Or why not calculate how much total light the lettuce needs from seedling to harvest and ratio it together with dark periods in order to avoid tip burn?
If you ever do another experiment, can you do one that tests for different ratio light and dark cycle duration with setup number 1?
Something like 12/6 (12hrs light, 6hrs dark), or 16/2(I heard this one works good), or 8/2(short cycles = more cycles from seed to harvest in less time).
Thanks
Interesting ideas! You should run some tests and share your results! :-)