I want some more Heliotropism!

I never felt more alive! Coming back to this forum today showed me what I have been missing these past years. People here caring, staying in touch as you discover new things in this science, I even remember everyone wishing each other merry christmas on the day before. So I first wanted to remind my old, and new friends here how good it feels to be here.

I wanted to talk about the leaves response to the direction of the sun like seen in real life outdoors but accomplishing this indoors without light tracking. I feel that as close as we can get to mimicking the real situation the better the results will be. Having light reach the plant from different angles has to be a big bonus, and I did this by alternating HPS and MH using fixed position hoods just above the plants. Since the light bulbs were both located in each hood (26 x 22), the distance was never too great as to loose the full intensity of the sun on the canopy.

Having an area of 9ft. x 4ft., the placement of the three sun-system 7 hoods would reach down into the canopy about 12in.; which means I had to grab the clones and skip the vegetive stage as so the plants would not want to grow too tall. The 38 plants looked like rows seen in an outdoor farmer's crop, primarily growing concentrated on the tops instead of root and foliage mass.

The heliotropism was accomplished when the morning MH lights turned off after six hours from sunrise, and this is when the intense sun came out using the HPS for the last 6 hours of the day. I am not sure how much of a role heliotropism played in this grow, there were so many other details like introducing co2 at such a high level that it allowed me to run the room at a tropical temp (82 degrees instead of 78), having fans on timers so they would delay and let the co2 fall in the air towards the canopy, using soil that was cured under a tarp avoiding chemicals that normally are used to correct the ph, and the amount of time used in the cure. So I wanted to single out this one topic about how plants chase the sun as the day moves on, and how we can do this today using newer equipment.

The sun-system 7 is no longer available since it has been 15 years from that time. Since the bulbs under the 26 x 22 hood were staggered underneath the foil reflector, could it be possible to find a similar hood today? Maybe using lesser expensive equipment which are just plain simple smaller hoods, fixed above the canopy and placed close to one another which may also accomplish the same goal. I want to use equivalent of 400 watt bulbs and similar spectrums of light found in these older MH, and HPS bulbs. The height of the canopy will not exceed approx 18 inches, and the width, and length of this canopy will be different today as opposed to my last situation. A little smaller in length and width, approx six feet long, and a little over two and half feet wide.

I have pictures to show you from my last structure what I used to grow back in 2006, click on my bio to see the pictures (or I can just put the pictures here for you). There has to be an efficient way to accomplish what I am trying to achieve, and I wanted to hear any feed back my new and old friends will have on this situation. I am outdated by about 15 years, so I want to know what I have missed since new equipment has come out (both concerning newer spectrum lighting, and heliotropism).

This is my first topic for a thread since coming back here to icmag, so let me add some pictures that will get you as excited. These are our my first pictures and were really only intended to show what materials I was using; the set up was not used exactly as shown. My first grow with that equipment was situated on a 4ft. x 8 ft. piece of plywood, manually fed using the Botanical chart of nutrients, organic peat moss from a horticultural farm from the West Coast (kinda cool getting soil shipped to me), Rand 7" Air Cone pots, two Botanicare 4ft. x 4ft. trays with a single 1ft. x 4ft. Botanical tray in the middle of the two; allowing four more plants (totaling 38). A CAP Co2 Generator was placed at the end of this structure higher towards to the top near the ceiling, and fans alternated using CAP timers. When it was cold outside, I used a humidifier to keep things right indoors.

A small greenhouse was used to keep the 38 clones inside, using a meter to measure the amount of humidity, a spray bottle with water did the rest. Clones were placed in organic plugs from the same supplier of the peat moss I used. The plugs held tight around the stalks of the clones and had a 100 percent success rate during the three years of my experimentation. Harvesting was done approx 7 to 8 weeks after the clones were placed under the full spectrum lighting, this depended on when I uprooted them since often I picked at different times depending on which kind of head high I was looking to achieve (using a microscope to verify the color of the trichosomes). A crawl space dehumidifier was placed under the uprooted plants hanging from the ceiling as they dried for a day or so then placed inside quart size jars so they would cure for at least a couple of months.

I wanted to see what you guys thought about my methods back then, and what you would do different today. Man, I stayed up all night checking out old threads on this forum when we I use to hang out here. I had to call in at work and tell them I was sick, I guess what I am saying is I am all excited all over again like this is my first time. Thanks for welcoming me back! Can not wait to give a smoke report of this "one hit wonder". And what is so cool, is I grew it!!!! Here are the pics I promised...



CW

If I dug back far enough I could find my threads on a circular grow operation with the surround lights (eight 6 tubes x 32 watts) on four timers so the light worked its way from one side to the other during the day. Overhead was 800 watts CMH.

Then I tried ten 400 watt overhead with the rims of the reflectors all touching one another

It is similar still, only with a combo of LED and CMH overhead and LED on the side. The plants are turned by hand twice a day, this actually turned out to be the easiest method to effectively get symmetrical growth, the heliotropism. With light coming in from every direction already it did not affect the plant much by merely altering the intensity of the lights in a particular direction. Either the plant or the light had to actually move for the plant to alter growth patterns.

At least that is what happened with me and my non standard garden.
Seventeen years of continual record keeping and testing and I lost two months of this year's crop to bad lighting.

A note, 24/0 Far Red enhancement does protect against light leaks but also swaps ALL bud growth to leaf growth and will continue in that mode for at least three months without slowing. The plants were under 5600 watts 12/12 overhead full spectrum the entire three months. Behind on electric bill now.

I started gardening about the time you stopped. I have gone through four major changes in lighting during that time.

HID to CMH to Blurple LED to sidelighting to full spectrum LED combined with CMH, Far Red, and UVB all on their own timers and plants on rotating bases.

Retired and this keeps my idle hands occupied. Actual physical labor is no longer an option, but indoor gardening is custom made for old folks with heart problems.

I try something new every single crop, it even comes out good sometimes.

Welcome back, I like your attitude.

Phaeton - really nice to meet you! I agree with this being a very healthy hobby, all the science, clean scrubbed air, foliage, and the hope of buds at the end of the trail make this one exciting science project. Before I dove into it I researched the heck out of it, not from this forum or popular books, but everywhere else. Then I bought all the equipment before starting because it would suck that I ran out of money when needing "that" piece of equipment. having good attitude is where it is at, and that is probably what I was commenting on when I said I met so many friends here that made me feel like I belonged.

I ad figured the lighting had changed over the years, pretty much the rest of the details elsewhere are all the same (substrate, nutrients, basic genetics, technique). But I wanted to try to do it the exact same way because I know it worked, and changing the lighting frequency sounds good but I have not used them.

Moving the plants around and turning them is not something I would want to do because the natal effect of the sun making the leaves tilt is healthy, and yes it also covers more of the plant with sun but that is not the reason why I was wanting to do it. Think of the wasted energy and stress of the plant always being placed in a different position when you turn it.

I was using magnetic ballasts that had both MH & HPS all in the same ballast with two ballasts built into one ballast enclosure and the timers were set for 6 hours on each one, on each ballast of the three different light fixtures that had two different lights in each hood. So what I am trying to find is a similar situation or design one myself using a small hood for each different light of these six bulbs. This helped out with electricity too, my bill was only about 60 bucks more, and my ac did not run all the time because I set the thermostat to 82 instead of 78 due to running so much Co2.

I like that you kept records, and I was wondering if a person cancels their membership here back 15 years ago if that grow documentation I made available here was still here? I found some pictures, so not everything gets deleted, and that is where those pics in my album came from. I was hoping to do what I did before but this time around spend less on the equipment, thus be even more efficient. I did not use air ducting for my hoods, I just let them run in the open space of the room and all my calculations for Co2 and my scuba were based on the entire square footage of the whole apartment. It was nice, I smoked cigarettes and you could not even smell that in the area either.

I try not to experiment with new techniques unless I made a mistake like trying to grow clones that I vexed for too long. Later I learned to just skip this phase and it produced wonderfully consistent results. When I did mess up with the height it was fun to alter the plants with screens and weave them in but it was too much work, and the results gave a much smaller yield. The camera loved taking pictures of those screens though, it looked cool set into the structure before I placed the plants back in the trays.

Should I look for used equipment like on eBay? It would be nice to get some more sun system 7 fixtures, and bulbs. I looked at Bontaincare and did notice trays that were any longer the size I had, I am interested in having 4ft. and what it it 8 inched wide (or some thing lie that. This way I can manipulate their position in my situation I don't have room for 4 x 4 trays any longer (it is more like a little over two and half feet by six feet. Or do you think I should use the current magnetic ballasts that are available and use ceramic 315 watt bulbs. Do you have any experience with these ceramic 315 bulbs. And are they available in both HPS and MH?

Phaeton - what stable genetics have you been using over this time. That is the other area I need to cover so I can get this show going again. I wanted to get some AK48 again, and something else while I am in the store.

CW

The dual lamp reflectors I see out now are all much bigger. Here are a couple examples:

https://growershouse.com/hydrofarm-8-raptor-reflector-with-dual-lamps

https://growershouse.com/nanolux-de-double-ended-dual-fixture-1200w-600x2

Edit: I take that back I did find one very similar to what you had:

http://www.alldayhydro.com/store/in...ydrofarm-growzilla-6-dual-bulb-reflector.html

ballast: https://www.amazon.com/Nanolux-Digital-Dimmable-Ballast-Light/dp/B00OQHZ82S

I've been thinking of a similar idea using LEDs. Basically using the Samsung strips like the quantum boards on 1" profile heat sinks. These strips would make a half circle above the plants. Using an Arduino and some relays, they could simulate the "sun" traveling through the "sky" with a single driver. You could even use the 3000K for "sunrise" and "sunset" and higher Kelvin for "noon".

Kelly1376 - Okay, it is challenging (make me think harder) when becoming friends with you, I can not thank you enough for that. I am going to post the information here along with some pictures and data from their sties so we all can see.

First I want to reiterate what heliotropism is for all the people who are not aware of this concept. It is listed in wikipedia if you all want to look further into the term but basically it is this: As the sun moves from east to west across the sky, the leaves actually follow it like little solar panels. Having the plant move like this must accomplish more than just getting the most out of the sun.One aspect is that as the sun rises the light frequency is different than around three on the after noon when it is at it's peak in frequency, and heat. Then as the sun sets it once again gives us a lower freq. and cooler temp. Maybe the plant is warming up as the day begins and then after a hard day in the sun it cools down kinda like in an exercise routine. The leaves as they move will allow the light to penetrate deeper into the canopy since one leaf has moved out of the way from in front of another. I noticed with two small oak trees in my backyard that the trees never touched one another as they were planted too close and I could see the leaves perform this heliotropism which initially gave me the idea to get the sun system 7 and stager the lights and also use different frequencies. My set up started with MH for a cool start, and the day ended with the warner HPS (6 hours each). Now this is a lot of ballasts, but the set up covered more area because of all the hoods and staggered light bulbs (which have to be staggered in order to cover the plants with both different bulbs).

I want to make sure other growers are not misunderstanding us here and think we are just trying to get light on the sides of the plant. The light will only penetrate so far into the canopy if you want the full 100% intensity of the sun (I have these charts in my gallery if you want to copy them). The flowers below this sun thermocline will not perform as well as the tops which is our primary focus. Really what we are doing here is getting maximum solar collection of the suns whole day and done in the same way as outdoors; except we get to see the results in two months (hehehehe). Let me upload those picture of this equipment. The sun system 7 equipment is already on my album if you want to take a look (the system 7 is 26 x 22 x 7)(external ballasts).

CW

I wanted to add something we were taught in school about the human body. Eustress is called the "good stress" of the human body and includes physical stressors (for example gravity). You here about gravity when astronauts go into space and the lack of gravity has all sorts of implications. here on this forum we talk about about bad stress, and how plants do not perform as well, and it can even cause the plant to change sex and produce seeds thinking it is the last plant on Earth thus needing to multiply so it's species survives. So "good stress" must be an overlooked topic, and maybe by accident we apply these principles but what if we were to more dial in on them and use their advantages.

Movement of the body influences circulation, even helps remove unwanted built up properties in the fluid so it will heal sooner. So the plant expereincing heliotropism with this movement may make nutrients spread throughout the plant better, and what this plant does with these nutrients after receiving them may also be more beneficial and distributed better. Or simply, the things we take for granite like good stress as seen with the example of gravity is required in order to replicate indoors what is happening outdoors naturally.

Stress which is artificially replicated, another example would be wind. If our fans are not blowing all the time and are on timers, especially if these timers are always changed and set to different intervals, and different lengths of how long they are turned on, or turned off; then this "good stress" would be something that we take fro granite in the outdoors yet forget about when we grow indoors.

Maybe even the stress of the nutrients not being consistent would be a good stress and make the plant search for food, not just in the roots but within the whole plant's body. Now doing this too much or too long would be bad and that would be seen in a plant that has more root mass than foliage mass above ground. Another example is aeroponics where the plant gets too much nutrients all the time and the root mass becomes very large as compared to the size of plant above this feeding tube. That is why I decided not to aeroponics and grow instead using hydroponics. here, gravity pulls the nutrients down through the column of the soil bathing the roots as it falls, and while it does it also lulls Co2 down the soil column and bathes the plant as well. That is why over watering is the sure fire way to kill any plant, the plant never gets to breathe.

But, what are we all missing here when we talk about these things above. If we don't know yet all the details maybe it would be wise to play it save and try to just mimic what happens outdoors even not knowing all the benefits. The is why I do not use substrates other than soil. Coco fibers as a substrate sounds good on one level, but already we know the ph is wrong, and in adding chemicals to correct this makes this plant no longer organic (natural). Even when using soil, most companies who sell it add chemicals even though it has a label calling it organic and this is a big problem at the grocery store (everyone is lying). Soil or peat moss should get it's ph naturally, and by not doing that causes problems.

Having your fans run all the time is also a stress, if you wanted to let Co2 fall with it's heaver weight than air, and fall into the canopy then your fans will prevent this by blowing it away, not letting it sit long enough to be naturally absorbed. So putting your fans on timers like we talked about earlier in our conversation not only creates stress like seen in gravity, it also lets nutrients from the air be taken in.

Even pests, and I know I will get some flack for this when saying it. But even the presence of posts may stress the plant in a good way, making it stronger, making chemicals in it's structure to activate to fight this stress may be a good thing; hence it is present in the outdoors. So I think we want to avoid too sterile an environment. Having things go wrong is natural in populations of people and populations of plants. Please don't go out and get cones from a friend who brought them to you from another house, or grown outdoors; I don't want people to believe that causing problems is a thing you want to to do that much. But I am trying to make a int that I think we are trying to make things too perfect when we grow. maybe letting your plants starve once and watch the leaves go limp before feeding again may just be a good thing!

CW

Hello, this is Chilly Willy with some exciting news. I was reading the Wikipedia page again and noticed something exciting. Heliotropism is not just the movement of leaves as the sun moves across the sky, Wikipedia says both the leaves and flowers change their position as this phenomena occurs.

Kelly1376 gave links above where you may find all the following equipment we are about to talk about, just click on his links so you may find out more. But I wanted to show everyone a few pictures, and some details that I found interesting.



Purchasing this piece of equipment allows you to remotely place the ballast, and then you can stager the light hoods where they are not lined up (unlike how it is interlay assembled). This will increase your footprint, and make for a lighter weight mounting of the hood. But you must purchase the 15 foot cords separate. You would not want to stager then too far cater-corner from each other, just somewhat so that you still get the intensity inside the canopy. This staggering will increase the heliotropism effect further than just mounting the lights as they are sold assembled.

The chart they supplied shows you an idea the reach of each light, just keep in mind that this is not the correct chart for what it is we are doing here. When you have more than the single purchase of this equipment, and buy multiple units then you may imagine just the MH portions of each purchased light aiming at the canopy for the the first half of the day which in my case is six hours. These MH lights will then turn off after the six hours and the HPS lights will all come on; thus the different position of the changed lights will make the leaves and flowers move towards them. This chart shows all the lights on at one time and that is a misrepresentation of what we are trying to achieve here. I guess a simple way to say how it should be: imagine one blue area of the chart on, then it turns off and an orange one come on, thus notching the different angle between the this two examples.

By alternating lights, as opposed to running all of them at one time, we become very efficient in supplying adequate light, different frequencies, and better over all coverage thus a larger footprint. As mentioned before, if you go a step further and remove the ballast from the hoods and stager the hoods in a somewhat slight cater-corner fashion this further achieves what we have already accomplished.

Lighting has come a long ways since 2006 when I was first processing this concept while using the sun-system 7. I see you can actually set the size of the intensity by dimming the bulbs. In my case growing lollipops in crop rows, I will be suing the 450W setting, which will give me 12 inches into the canopy where I am focused on primarily interested in growing the buds.

The size and distance of each hood and it's proximity of each other when mounted will be almost exactly what I used as a footprint when I did this before, having consistent results in each grow during those three years. The grow was documented here in 2006 and 2007 and if any of you find this information please let me know. It's hard to forget this stuff, so having that information is no big deal. I am looking forward to doing it again and using newer equipment. I may be wrong, but the bulbs today are not much better than back then; I think I read it is a ten percent difference.

I see this system does not use fans in the hoods, so I will need to do my calculations for the entire living space and not just the growth area. I have a question though for you guys who know about the newer equipment. Do I still need to use light timers for each ballast on each and every one, or can I purchase the module that can be bought outside the initial purchase so that a computer will turn them on and off during these six hour cycles?

I wanted to note that the last picture above although it shows why staggering lights cater-corner improves our idea, that particular system does not allow the same kind of flexibility as the system with the other three pictures. But it is a perfect example of mixing the lights, the lights being slightly apart from each other, and also slightly cater-corner. Which all adds up to making the plants move as they are feed light, yet not too far away from the light that they have to reach and become stretched in the stems.

ReikoX - Hey, it is awkward getting started here posting again, I think you noticed my excitement and mistakes on that thread the other day; sorry.

can you post some more about what you mentioned above. Pictures would be great, along with your thoughts on how this would better move the plant so it captures the full effect of the sun. I am new to the newer equipment, so can you begin by explaining what LED does differently to the plants, and it's other features and benefits. I am sure it is not as loud as a magnetic ballast, it may be lighter in weight and cost. What kind of heat does it produce? It's really nice to meet you, and look forward to talking further with you as I grow. Pun intended. Thanks for you good input here.

No worries about any misunderstanding. Tone never comes through in text.

LED is different than HPS in two major ways. The first major difference is LED is directional lighting. A HID bulb gives off light in all directions, this is why we use hoods with reflectors. A LED gives off light in one direction, usually around 120°, this usually eliminates the reflector. The second major difference is LED can be more efficient. A HID bulb produces a certain number of photons and the rest is released as radiant heat. A LED produces more photons and less heat for the watts used.

LED changes fast and right now the Samsung reel LED are all the rage. These are available in several spectrums from "cool" (like MH) to "warm" (like HPS). You have probably seen the cheaper version of these in big box stores. These LED are usually mounted to a heat sink like a computer processor. For this design they would be mounted on a 40" length of 1" wide extruded heat sink. I was thinking seven or eight of them, but haven't done the research on wattage yet. Each one would run the length of the 4x4 footprint. They would be angled in an arc above the plants. As you can see in the sketch below, turning the lights on will change the angle of the lights.



The final piece to this puzzle is the control of the lighting. Like an HID uses a ballast, LED uses a driver. Now we could use multiple drivers and timers, but that gets expensive fast! So, instead we can use an Ardunio microcontroller to control our lighting. Similar to a flip/flop, we can use relays to swap which strip is getting power. With a dimmable driver, the possibilities are endless. For example a lower power for the first and last hours.

This probably wouldn't cost TOO much more than HID hoods and ballasts. The heatsinks are reasonable at around $10 each plus shipping. The LED strips are about $25 each plus shipping. A good dimmable driver can be had for around $70 plus shipping. Finally the Ardunio and relays would run you another $25 or so. So for the 8 strip option we are looking at around $350-$400.

Unfortunately this design is NOT plug and play. It requires a good bit of DIY as well as programming the microcontroller.

*Edit* a quick look and I realized these strips are roughly 35 watts each, so for the 4x4 area we would probably want 16 strips and running them four at a time. Still with double the strips it's still only around $650-$700.

ReikoX - Man, I don't even know what to say, lighting has come a long way. Your idea like you said allows a ton of manipulation. I just got off the Philips site on the section where they teach you about what all id going down in the latest in lighting and the first big thing that popped up was this big write up about how LED is cutting the edges in commercial lighting. This is a good area to visit if you have time, there are videos, articles, and workshops. I am really glad you came here and are sharing your excitement with what you have been learning about LED for grow ReikoX.

Philups has an amazing site to look through, there is even a section where you can read about trends, which include videos and all sorts of stuff. They also have a lot of charts and very detailed spec sheets for each bulb. I was just on there checking out ceramic metal halides. I like the fact that when they are on, others just think you have white lights on in your place. These metal halides of today even have some red spectrum in them, lighting has changed a lot over the years; I like these new ceramic bulbs.

If you guys want to see what all I was reading, come take a look later on in my photo album here. I will include the spec sheets, and spectrum charts, and footprint area covered. The specific bulb that I collected all this data for is the Philups CDM-T Elite 315W/942 PGZ18.1CT/12

You seem enough of a lighting enthusiast it would probably help you to learn about daily light integral, ppfd, umol, photons etc. Historically growers really only talked in terms of watts, but watts don't really mean anything, it's photon efficiency that matters. Watts in = photons out. Here's an interesting paper pay particular attention to pgs 5 & 6:

https://growershouse.com/images/PDFs/BUGBEEpub__6441190.pdf

Good read on Par, PPFD:

https://fluence.science/science/par-ppf-ppfd-dli/

Good read on daily light integral:
https://www.extension.purdue.edu/extmedia/ho/ho-238-w.pdf

Oh yeah and you will probably like this thread:

https://www.icmag.com/ic/showthread.php?t=293045

Some of the newer cob led setups have a photon efficiency over 2. I believe fluence does as well. Lots of folks been making their own cob lights check out timbergrowlights.com for some examples.

Thanks for the links Kelly. There is some very useful information in those papers.

Kelly1376 - you are I are on the same thoughts, I been reading all this material I grabbed, and it is talks about all of this more in depth. I also found some documented growths outside of our stuff that is really detailed, this showing the comparison of lights and the results in yield, distance between nodes.

Dude, I had no idea that the light spectrum chart was just a chunk of a bigger chart that includes so much stuff (for example radio frequency). That atoms wobble, tun over, and all these different ways atoms are affected, in turn other items perceive them (such as our eyes seeing light is done by one of those methods).

I been also reading how temperature, Co2, intensity, and wave length all take a role in the growth. Just Co2 alone when you amplify this that this is a different cycle in the plant than what is going on with the cycle in turning light into energy. That this guy did an experiment and found that light is what gives plants their mass and not the nutrients.

Also, some of these experiments show that it is not the HPS that gives the mass, it is the intensity. And that that a plant may only require a certain amount and this may even be a low amount in order for it take advantage of say the blue light. I mean this is really cool stuff.

You should go to the Wikipedia page on photosynthesis and after reading it, click on the links at the bottom. There are also some good links at the bottom of the Wiki page on Grow lighting. That is where I found some of the grow documents on other plants with all those details. Did you know that there are meters not to measure the photosynthesis but measure the Co2 synthesis which in turns tells you how well the plant is taking up light and using it. I say those meters on the internet and they were only around 350 bucks, they also had some that were around a couple grand.

I want to do my next grow using more science, and I am finding out be careful what you wish for (it may come true). It helps knowing the history and also helps knowing the history of bulbs. I been a this for the past two days. You inspired me to work harder Kelly, thanks again for that. hehehehe ... My buds just made a freind!

https://hortsci.ashspublications.org/content/30/2/374.full.pdf

Here is guy who grew potatoes indoors with three different grows using different types of light them measuring the node distance and mass of the dried product. He duplictaed his attempts and got the same results. It's very informative.

Jan van Helmont began the research of the process in the mid-17th century when he carefully measured the mass of the soil used by a plant and the mass of the plant as it grew. After noticing that the soil mass changed very little, he hypothesized that the mass of the growing plant must come from the water, the only substance he added to the potted plant. His hypothesis was partially accurate — much of the gained mass also comes from carbon dioxide as well as water. However, this was a signaling point to the idea that the bulk of a plant's biomass comes from the inputs of photosynthesis, not the soil itself.

Robert Emerson discovered two light reactions by testing plant productivity using different wavelengths of light. With the red alone, the light reactions were suppressed. When blue and red were combined, the output was much more substantial. Thus, there were two photosystems, one absorbing up to 600 nm wavelengths, the other up to 700 nm. The former is known as PSII, the latter is PSI. PSI contains only chlorophyll "a", PSII contains primarily chlorophyll "a" with most of the available chlorophyll "b", among other pigment. These include phycobilins, which are the red and blue pigments of red and blue algae respectively, and fucoxanthol for brown algae and diatoms. The process is most productive when the absorption of quanta are equal in both the PSII and PSI, assuring that input energy from the antenna complex is divided between the PSI and PSII system, which in turn powers the photochemistry.

Louis N.M. Duysens and Jan Amesz discovered that chlorophyll a will absorb one light, oxidize cytochrome f, chlorophyll a (and other pigments) will absorb another light, but will reduce this same oxidized cytochrome, stating the two light reactions are in series.

There are three main factors affecting photosynthesis and several corollary factors. The three main are:Light irradiance and wavelengthCarbon dioxide concentrationTemperature.

In the early 20th century, Frederick Blackman and Gabrielle Matthaei investigated the effects of light intensity (irradiance) and temperature on the rate of carbon assimilation. At constant temperature, the rate of carbon assimilation varies with irradiance, increasing as the irradiance increases, but reaching a plateau at higher irradiance. At low irradiance, increasing the temperature has little influence on the rate of carbon assimilation. At constant high irradiance, the rate of carbon assimilation increases as the temperature is increased. These two experiments illustrate several important points: First, it is known that, in general, photochemical reactions are not affected by temperature. However, these experiments clearly show that temperature affects the rate of carbon assimilation, so there must be two sets of reactions in the full process of carbon assimilation. These are, of course, the light-dependent 'photochemical' temperature-independent stage, and the light-independent, temperature-dependent stage. Second, Blackman's experiments illustrate the concept of limiting factors. Another limiting factor is the wavelength of light. Cyanobacteria, which reside several meters underwater, cannot receive the correct wavelengths required to cause photoinduced charge separation in conventional photosynthetic pigments. To combat this problem, a series of proteins with different pigments surround the reaction center. This unit is called a phycobilisome.

As carbon dioxide concentrations rise, the rate at which sugars are made by the light-independent reactions increases until limited by other factors. RuBisCO, the enzyme that captures carbon dioxide in the light-independent reactions, has a binding affinity for both carbon dioxide and oxygen. When the concentration of carbon dioxide is high, RuBisCO will fix carbon dioxide. However, if the carbon dioxide concentration is low, RuBisCO will bind oxygen instead of carbon dioxide. This process, called photorespiration, uses energy, but does not produce sugars.

RuBisCO oxygenase activity is disadvantageous to plants for several reasons: One product of oxygenase activity is phosphoglycolate (2 carbon) instead of 3-phosphoglycerate (3 carbon). Phosphoglycolate cannot be metabolized by the Calvin-Benson cycle and represents carbon lost from the cycle. 1) A high oxygenase activity, therefore, drains the sugars that are required to recycle ribulose 5-bisphosphate and for the continuation of the Calvin-Benson cycle. 2) Phosphoglycolate is quickly metabolized to glycolate that is toxic to a plant at a high concentration; it inhibits photosynthesis. 3) Salvaging glycolate is an energetically expensive process that uses the glycolate pathway, and only 75% of the carbon is returned to the Calvin-Benson cycle as 3-phosphoglycerate. The reactions also produce ammonia (NH3), which is able to diffuse out of the plant, leading to a loss of nitrogen.


Russian botanist Andrei Famintsyn was the first to use artificial light for plant growing and research (1868).

Output spectrum of a typical metal-halide lamp showing peaks at 385nm, 422nm, 497nm, 540nm, 564nm, 583nm (highest), 630nm, and 674nm.

According to the inverse-square law, the intensity of light radiating from a point source (in this case a bulb) that reaches a surface is inversely proportional to the square of the surface's distance from the source (if an object is twice as far away, it receives only a quarter the light) which is a serious hurdle for indoor growers, and many techniques are employed to use light as efficiently as possible. Reflectors are thus often used in the lights to maximize light efficiency. Plants or lights are moved as close together as possible so that they receive equal lighting and that all light coming from the lights falls on the plants rather than on the surrounding area.

With the introduction of ceramic metal halide lighting and full-spectrum metal halide lighting, they are increasingly being utilized as an exclusive source of light for both vegetative and reproductive growth stages.

If high-pressure sodium lights are used for the vegetative phase, plants grow slightly more quickly, but will have longer internodes, and may be longer overall.

Natural daylight has a high color temperature (approximately 5000-5800 K).

PAR designates the spectral range of solar radiation from 400 to 700 nanometers, which generally corresponds to the spectral range that photosynthetic organisms are able to use in the process of photosynthesis.

The irradiance of PAR can be expressed in units of energy flux (W/m2), which is relevant in energy-balance considerations for photosynthetic organisms. However, photosynthesis is a quantum process and the chemical reactions of photosynthesis are more dependent on the number of photons than the amount of energy contained in the photons.[39] Therefore, plant biologists often quantify PAR using the number of photons in the 400-700 nm range received by a surface for a specified amount of time, or the Photosynthetic Photon Flux Density (PPFD).[39] This is normally measured using mol m−2s−1.According to one manufacturer of grow lights, plants require at least light levels between 100 and 800 μmol m−2s−1.[40] For daylight-spectrum (5800 K) lamps, this would be equivalent to 5800 to 46,000 lm/m2.

Visible light lies toward the shorter end, with wavelengths from 400 to 700 nanometres.

For most of history, visible light was the only known part of the electromagnetic spectrum. The ancient Greeks recognized that light traveled in straight lines and studied some of its properties, including reflection and refraction. The study of light continued, and during the 16th and 17th centuries conflicting theories regarded light as either a wave or a particle.[6]The first discovery of electromagnetic radiation other than visible light came in 1800, when William Herschel discovered infrared radiation.[7] He was studying the temperature of different colors by moving a thermometer through light split by a prism. He noticed that the highest temperature was beyond red. He theorized that this temperature change was due to "calorific rays" that were a type of light ray that could not be seen.The next year, Johann Ritter, working at the other end of the spectrum, noticed what he called "chemical rays" (invisible light rays that induced certain chemical reactions). These behaved similarly to visible violet light rays, but were beyond them in the spectrum.[8] They were later renamed ultraviolet radiation.

There are no precisely defined boundaries between the bands of the electromagnetic spectrum; rather they fade into each other like the bands in a rainbow (which is the sub-spectrum of visible light). Radiation of each frequency and wavelength (or in each band) has a mix of properties of the two regions of the spectrum that bound it. For example, red light resembles infrared radiation in that it can excite and add energy to some chemical bonds and indeed must do so to power the chemical mechanisms responsible for photosynthesis and the working of the visual system.

The Sun emits its peak power in the visible region, although integrating the entire emission power spectrum through all wavelengths shows that the Sun emits slightly more infrared than visible light.

Visible light (and near-infrared light) is typically absorbed and emitted by electrons in molecules and atoms that move from one energy level to another. This action allows the chemical mechanisms that underlie human vision and plant photosynthesis. The light that excites the human visual system is a very small portion of the electromagnetic spectrum. A rainbow shows the optical (visible) part of the electromagnetic spectrum; infrared (if it could be seen) would be located just beyond the red side of the rainbow with ultraviolet appearing just beyond the violet end.

Electromagnetic radiation with a wavelength between 380 nm and 760 nm (400–790 terahertz) is detected by the human eye and perceived as visible light. Other wavelengths, especially near infrared (longer than 760 nm) and ultraviolet (shorter than 380 nm) are also sometimes referred to as light, especially when the visibility to humans is not relevant. White light is a combination of lights of different wavelengths in the visible spectrum. Passing white light through a prism splits it up into the several colors of light observed in the visible spectrum between 400 nm and 780 nm.

The behavior of EMR depends on its wavelength. Higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths. When EMR interacts with single atoms and molecules, its behavior depends on the amount of energy per quantum it carries.EMR in the visible light region consists of quanta (called photons) that are at the lower end of the energies that are capable of causing electronic excitation within molecules, which leads to changes in the bonding or chemistry of the molecule.

In developmental biology, photomorphogenesis is light-mediated development, where plant growth patterns respond to the light spectrum. This is a completely separate process from photosynthesis where light is used as a source of energy. Phytochromes, cryptochromes, and phototropins are photochromic sensory receptors that restrict the photomorphogenic effect of light to the UV-A, UV-B, blue, and red portions of the electromagnetic spectrum.[1]The photomorphogenesis of plants is often studied by using tightly frequency-controlled light sources to grow the plants. There are at least three stages of plant development where photomorphogenesis occurs: seed germination, seedling development, and the switch from the vegetative to the flowering stage (photoperiodism).[2]

Typically, plants are responsive to wavelengths of light in the blue, red and far-red regions of the spectrum through the action of several different photosensory systems. The photoreceptors for red and far-red wavelengths are known as phytochromes. There are at least 5 members of the phytochrome family of photoreceptors. There are several blue light photoreceptors known as cryptochromes. The combination of phytochromes and cryptochromes mediate growth and the flowering of plants in response to red light, far-red light, and blue light.

Plants use phytochrome to detect and respond to red and far-red wavelengths. Phytochromes are signaling proteins that promote photomorphogenesis in response to red light and far-red light.[5] Phytochrome is the only known photoreceptor that absorbs light in the red/far red spectrum of light (600-750 nm) specifically and only for photosensory purposes.[1] Phytochromes are proteins with a light absorbing pigment attached called a chromophore. The chromophore is a linear tetrapyrrole called phytochromobilin.[6]There are two forms of phytochromes: red light absorbing, Pr, and far-red light absorbing, Pfr. Pfr, which is the active form of phytochromes, can be reverted to Pr, which is the inactive form, slowly by inducing darkness or more rapidly by irradiation by far-red light.[5] The phytochrome apoprotein, a protein that together with a prosthetic group forms a particular biochemical molecule such as a hormone or enzyme, is synthesized in the Pr form. Upon binding the chromophore, the holoprotein, an apoprotein combined with its prosthetic group, becomes sensitive to light. If it absorbs red light it will change conformation to the biologically active Pfr form.[5] The Pfr form can absorb far red light and switch back to the Pr form. The Pfr promotes and regulates photomorphogenesis in response to FR light, whereas Pr regulates de-etiolation in response to R light.[5]Most plants have multiple phytochromes encoded by different genes. The different forms of phytochrome control different responses but there is also redundancy so that in the absence of one phytochrome, another may take on the missing functions.[5] There are five genes that encode phytochromes in the Arabidopsis thaliana genetic model, PHYA-PHYE.[6] PHYA is involved in the regulation of photomorphogenesis in response to far-red light.[5] PHYB is involved in regulating photoreversible seed germination in response to red light. PHYC mediates the response between PHYA and PHYB. PHYD and PHYE mediate elongation of the internode and control the time in which the plant flowers.[6]Molecular analyses of phytochrome and phytochrome-like genes in higher plants (ferns, mosses, algae) and photosynthetic bacteria have shown that phytochromes evolved from prokaryotic photoreceptors that predated the origin of plants.

Plants contain multiple blue light photoreceptors which have different functions. Based on studies with action spectra, mutants and molecular analyses, it has been determined that higher plants contain at least 4, and probably 5, different blue light photoreceptors.Cryptochromes were the first blue light receptors to be isolated and characterized from any organism, and are responsible for the blue light reactions in photomorphogenesis.[6] The proteins use a flavin as a chromophore. The cryptochromes have evolved from microbial DNA-photolyase, an enzyme that carries out light-dependent repair of UV damaged DNA.[9] Two cryptochromes have been identified in plants. There are two different forms of crytochromes, CRY1 and CRY2, which regulate the inhibition of hypocotyl elongation in response to blue light.[9] Cryptochromes control stem elongation, leaf expansion, circadian rhythms and flowering time. In addition to blue light, cryptochromes also perceive long wavelength UV irradiation (UV-A).[9] Since the cryptochromes were discovered in plants, several labs have identified homologous genes and photoreceptors in a number of other organisms, including humans, mice and flies.[9]There are blue light photoreceptors that are not a part of photomorphogenesis. For example, phototropin is the blue light photoreceptor that controls phototropism.

Plants show various responses to UV light. UVR8 has been shown to be a UV-B receptor.[10]

In plants, cryptochromes mediate phototropism, or directional growth toward a light source, in response to blue light. This response is now known to have its own set of photoreceptors, the phototropins.Unlike phytochromes and phototropins, cryptochromes are not kinases. Their flavin chromophore is reduced by light and transported into the cell nucleus, where it affects the turgor pressure and causes subsequent stem elongation. To be specific, Cry2 is responsible for blue-light-mediated cotyledon and leaf expansion. Cry2 overexpression in transgenic plants increases blue-light-stimulated cotyledon expansion, which results in many broad leaves and no flowers rather than a few primary leaves with a flower.[18] A double loss-of-function mutation in Arabidopsis thaliana Early Flowering 3 (elf3) and Cry2 genes delays flowering under continuous light and was shown to accelerate it during long and short days, which suggests that Arabidopsis CRY2 may play a role in accelerating flowering time during continuous light.[19]

Cryptochromes receptors cause plants to respond to blue light via photomorphogenesis. Cryptochromes help control seed and seedling development, as well as the switch from the vegetative to the flowering stage of development. In Arabidopsis, it is shown that cryptochromes controls plant growth during sub-optimal blue-light conditions.[21]


Phytochrome is a photoreceptor and a pigment that plants, and some animals, use to detect light. It is sensitive to light in the red and far-red region of the visible spectrum. Many flowering plants use it to regulate the time of flowering based on the length of day and night (photoperiodism) and to set circadian rhythms. It also regulates other responses including the germination of seeds (photoblasty), elongation of seedlings, the size, shape and number of leaves, the synthesis of chlorophyll, and the straightening of the epicotyl or hypocotyl hook of dicot seedlings. It is found in the leaves of most plants.

Phytochrome consists of two identical chains (A and B). Each chain has a PAS domain and GAF domain. The PAS domain serves as a signal sensor and the GAF domain is responsible for binding to cGMP and also senses light signals. Together, these subunits form the phytochrome region, which regulates physiological changes in plants to changes in red and far red light conditions. In plants, red light changes phytochrome to its biologically active form, while far red light changes the protein to its biologically inactive form.

Phytochromes are characterised by a red/far-red photochromicity. Photochromic pigments change their "colour" (spectral absorbance properties) upon light absorption. In the case of phytochrome the ground state is Pr, the r indicating that it absorbs red light particularly strongly. The absorbance maximum is a sharp peak 650–670 nm, so concentrated phytochrome solutions look turquoise-blue to the human eye. But once a red photon has been absorbed, the pigment undergoes a rapid conformational change to form the Pfr state. Here fr indicates that now not red but far-red (also called "near infra-red"; 705–740 nm) is preferentially absorbed. This shift in absorbance is apparent to the human eye as a slightly more greenish colour. When Pfr absorbs far-red light it is converted back to Pr. Hence, red light makes Pfr, far-red light makes Pr. In plants at least Pfr is the physiologically active or "signalling" state.

Around 1989, several laboratories were successful in producing transgenic plants which produced elevated amounts of different phytochromes (overexpression). In all cases the resulting plants had conspicuously short stems and dark green leaves. Harry Smith and co-workers at Leicester University in England showed that by increasing the expression level of phytochrome A (which responds to far-red light), shade avoidance responses can be altered.[5] As a result, plants can expend less energy on growing as tall as possible and have more resources for growing seeds and expanding their root systems. This could have many practical benefits: for example, grass blades that would grow more slowly than regular grass would not require mowing as frequently, or crop plants might transfer more energy to the grain instead of growing taller.

I went through a chain of wikipedia pages, one leading to another; those are what I copied and pasted from there. .... Nudge ... wake up! hehehehe

I wanted to learn more about what is going on with lighting. Vendors try to sell the latest mouse trap and I just to make sure it is going to catch something before I buy it. It would be nice to have an efficient lighting system. It's the last detail.

The strain, grow medium, containers, nutrients, Co2, air exchange, drying & cure are all already dialed in. (back flip, and another and then a big smile).

The most efficient setups are gonna be cob setups or double ended HPS like gavitas. Gavitas are over 40% efficient and just damn powerful at +1000 watts and ~2100 umol output per lamp. To duplicate that with other setups would cost a lot. I kinda like your original dual bulb setup in the OP though. I suppose you could duplicate that with cobs you could build something similar to this with different kelvin temp:

http://timbergrowlights.com/100-watt-citizen-clu048-linear-framework/

Put 2 side by side and run a 5000k on one side and a 2500k on the other.

kelly1376 said:

The most efficient setups are gonna be cob setups or double ended HPS like gavitas. Gavitas are over 40% efficient and just damn powerful at +1000 watts and ~2100 umol output per lamp. To duplicate that with other setups would cost a lot. I kinda like your original dual bulb setup in the OP though. I suppose you could duplicate that with cobs you could build something similar to this with different kelvin temp:

https://timbergrowlights.com/100-watt-citizen-clu048-linear-framework/

Put 2 side by side and run a 5000k on one side and a 2500k on the other.

Click to expand...

Timber

1. Copied lights i was building to instigate a fight

2. Originally optic selling bottom of the barrel reseller lights from China

3. Now sells parts with a plug installed at a markup

4. Ad campaign everywhere and anywhere

5. Followers, probably workers, instigating fights

6. Their first light was in a tool box that over heated with customers not getting any response


Hello timber or fluence. Whoever you are

Not recommended. Check out gayapex for cob lights. Straight from Asia and fully built with what looks like decent features.

The Ursa or starlight? that advertises here looks like one of the better leds also.

I'd say your on the right path with cmh. Let led grow up

I could expand on that, meh, not worth the time
2 cents

They can't even respect the path your on...