Why go 24 hours lights on??

[Japanfreakier]

As far as growing it's not wrong. Any technique in growing can be explained easily.

 

[statusquo]

I agree. But how is one supposed to find the ideal techniques without any of the knowledge behind the subject as a whole?

 

[Japanfreakier]

The thing is that most of the stuff out there that people talk about is just bunk, so honestly I don't trust any of it till I test it out myself. It's nice and all for people to go on and on about controlling the DIL but till they tell me how to do that with my one light it's useless. And I've noticed that when you try to nail these people down to actually give some real world advice it's not there.

 

[statusquo]

Fair enough. I can definitely see where you're comin from. The only question I have is that how do you know your methods are idyllic if all you have to compare against is your own experience and the flawed/idyllic experience of others? (Not knocking on your methods, certainly, as you have results to show and my methods are FAR from idyllic haha.)

 

[Japanfreakier]

I don't know that my methods are ideal, I only know that compared to different light schedules they give me more final total weight in a shorter time. There might be more efficient way but nobody in this thread has suggested any. I think Spurr is suggesting something like putting a filter over the lights or something like that but it sounds like he hasn't actually done it himself, so no real experience unless I missed it.

 

[SumDumGuy]

Fwiw: Light to a plant is like weights to a body builder. The more weight then the more muscle. Just makes sense doesn't it. Do plants need sleep? Yes and they'll get 12 hours of it every night in the flowering cycle.

Y ahora con eso dicho lla dejen esta pelea.. No tiene razon muchachon!!

 

[B. Friendly]

The thing is that most of the stuff out there that people talk about is just bunk, so honestly I don't trust any of it till I test it out myself. It's nice and all for people to go on and on about controlling the DIL but till they tell me how to do that with my one light it's useless. And I've noticed that when you try to nail these people down to actually give some real world advice it's not there.

come on nothing I have said is not from experience or have not tried or read from a credible source. For the record all my post and threads, which I have many are good tried and tested methods.
Damn Jorge Cervantes, he's an idiot from this thread on...

 

[Japanfreakier]

lol, not talking about you B, unless you are also spurr.

 

[guambomb813]

- Statusquo - Yeah I've been sourcing as many different ways as I can to better understand! I didn't think to search here at icmag haha what an idiot I am. I'm used to doing the research after reading studies or articles or threads/posts that I do not quite understand.
On a side now this is some great info on lighting that Im glad to read up on get a better understanding for.

 

[guambomb813]

As far as growing it's not wrong. Any technique in growing can be explained easily.

Id agree for sure. The techniques themselves should be able to be explained in a way we can all understand. I can see how it might be difficult to go further in detail keeping simplified reasoning's explaining why the techniques being suggested are used and whats going down on the science side of the coin.

Im just glad to see this thread working in a positive direction. There will always be debate on topics, it's just a matter if we can all come to a better understanding with everybody's info/rebuttals given.

 

[spurr]

The thing is that most of the stuff out there that people talk about is just bunk, so honestly I don't trust any of it till I test it out myself. It's nice and all for people to go on and on about controlling the DIL but till they tell me how to do that with my one light it's useless. And I've noticed that when you try to nail these people down to actually give some real world advice it's not there.

OK Japan, let try this again, water under the bridge OK?

I told you how to control DLI many times in this thread, maybe you missed it because it was inside bigger posts, but I did tell you. And I also fully explained DLI too, like on page 3. Please, re-read my posts in this thread.

I will try to explain it again (for the last time):

DLI is the sum of light per day, it is found using PPFD (Photosynthetic Photon Flux Density); the number of photons within PAR range [400-700 nm] striking an area of 3'x3' per second. However, use of Lux or lumens can be used to find DLI but it's more inaccurate by around 5-15% because of the inaccuracy of converting from Lux or lumens to PPFD.

To increase DLI you can do two things: (1) increase irradiance (light intensity at canopy measured as a single instance, ex. per second); or (2) increase the hours of day light.

Like I wrote to you twice, your setup (with 400w and 250w) has lower PPFD (irradiance) than other gardens with higher wattege lamps (all else being equal such as proper distance to canopy which affects irradiance).

To increase your DLI while also decreasing your hours per day, so you are able to give you plants a night, simply increase the irradiance by: (a) moving your lights closer to the canopy; or (b) using bigger wattage lamps.

If you have a light meter I can tell you how to calculate DLI. For PPFD it's uber easy:

In the example below PPFD is umoles/meter^2/second. And umoles are photons within PAR range (400-700 nm). The 3,600 is seconds per hour.
​

• (PPFD x 3,600 x hour of light per day) / 1,000,000 = moles/meter^2/day

Please read these posts of mine again from this thread, all but the first three are to you:


1. why using 24/0 is not good for plants, also see the quoted section about ideal PPFD and DLI for cannabis; taken from my thread about red to far-red ratio
https://www.icmag.com/ic/showpost.php?p=3996203&postcount=28


2. this is where I wrote more about DLI
https://www.icmag.com/ic/showpost.php?p=3996256&postcount=32


3. why night time doesn't need to 100% dark
https://www.icmag.com/ic/showpost.php?p=3998707&postcount=44


4. why using weight isn't a good measure of efficacy of hours per day in veg
https://www.icmag.com/ic/showpost.php?p=3999050&postcount=48


5. why your use of lower irradiance means you need longer hours for higher DLI, and how to fix it
https://www.icmag.com/ic/showpost.php?p=4000626&postcount=74


6. I explain why you see more growth with longer hours, but also why you would see even more growth with less hours if you pack in more light in those less hours
https://www.icmag.com/ic/showpost.php?p=4000929&postcount=85


7. I explain that a 400w and 1000w will grow plants equally well if they both provide the same DLI, and why they don't provide the same DLI
https://www.icmag.com/ic/showpost.php?p=4000939&postcount=87



Here are good references you should read:


1. Daily Light Integral Defined
By Erik Runkle
http://www.gpnmag.com/Daily-Light-Integral-Defined-article7534


2. Measuring Daily Light Integral in a Greenhouse
Ariana P. Torres and Roberto G. Lopez
Department of Horticulture and Landscape Architecture, Purdue University
(a must read, great charts and data!)
http://www.extension.purdue.edu/extmedia/HO/HO-238-W.pdf


3. Daily Light Integral: A useful tool for the U.S. Floriculture industry
James E. Faust
(info about footcandles, PPFD, etc.)
http://www.specmeters.com/pdf/articles/A051.pdf


4. "Feature Article: A Different Look at Lighting: Effects of Prolonged Photoperiod, Spectral Quality, and Light Dosage"
http://www.advancedaquarist.com/2009/5/aafeature


5. Ready Research Results: Daily Light Integral & Flowering Of Annuals
Take your crop production to the next level with the latest findings from the Floriculture Research Alliance.
By Matthew Blanchard and Erik Runkle
Novemnver, 2010
http://www.greenhousegrower.com/magazine/?storyid=3892


6. The Effect of Daily Light Integral on Bedding Plant Growth and Flowering
James E. Faust, Veronda Holcombe, Nihal C. Rajapakse, and
Desmond R. Layne
HortScience - Volume 40, Number 3 - June 2005
http://www.clemson.edu/hort/Peach/pdfs/FaustHortScience2005.pdf



Here is a worthwhile study that explains why excess starch levels can inhibit biomass production by plant:

Starches are built up in the day in plants, and degraded into carbon at night that is used by the plant to grow. That is another reason why a night time is important (to prevent starch excesses).

Branches of a healthy plants getting sufficient irradiation should have plenty of starches; but branches lower on plants not in direct irradiation will have lower starches.

Arabidopsis thaliana is a "model organism" for plants, its' DNA has been fully sequenced and its an ideal model organism for plants. Like how mice are model organisms for humans in drug trials. Thus data collected from testing Arabidopsis thaliana is valid for most all other plants, including cannabis.

Cannabis isn't special, studies on many other C3 plants are fully usable for cannabis in most cases, especially with Arabidopsis thaliana.

"Starch as a major integrator in the regulation of plant growth"
PNAS June 23, 2009 vol. 106 no. 25 10348-10353
http://www.pnas.org/content/106/25/10348.full.pdf+html




Here are very good, and short, reports for a NASA workshop on using lighting to grow plants. Lots of topics covered, but these reports covering light (as hours) per day and the effects it has are of most interest to this thread:

These show why using more than 18-20 hours of light per day is not good. More than 17 hours can be deleterious, that is why I have tested 16/8, 17/7, 18/6, 20/4 and 24/0. If you don't believe me that plants do best when they have a night time (for light-independent reactions) I hope you will believe NASA!

1. LIGHT PERIOD REGULATION OF CARBOHYDRATE PARTITIONING (Short Report)
Harry W. Janes
http://www.controlledenvironments.org/Light1994Conf/1_6_Janes/Janes text.htm


2. EFFECTS OF RADIATION QUALITY, INTENSITY, AND DURATION ON PHOTOSYNTHESIS AND GROWTH
Bruce Bugbee
http://www.controlledenvironments.org/Light1994Conf/1_5_Bugbee/Bugbee text.htm


3. REGULATION OF ASSIMILATE [strach] PARTITIONING BY DAYLENGTH AND SPECTRAL QUALITY
Steve J. Britz
http://www.controlledenvironments.org/Light1994Conf/1_2_Britz/Britz text.htm


Here is the contents of the 1994 NASA workshop, some info is outdated, such as incorrect use of term PAR, but most info is spot on, see the seconds under "Photosynthesis"

International Lighting in Controlled Environments Workshop
T.W.Tibbitts (editor) 1994 NASA-CP-95-3309
http://www.controlledenvironments.org/Light1994Conf/Contents.htm
​

 

[spurr]

Spurr, do you think that quantifying the starch test through the glucose as you've described would be practical in our usage in quickly finding the best of the cuttings we take? I'm not sure of all methods that can be used to quantify the test in a practical manor in terms of clone selection so if you could further explain?

For quickly finding cuttings with highest starch levels I think using using iodine method is fine. I thought you were going to carry out more in depth experiments, that is why I suggested the conversion to glucose.

 

[spurr]

I don't know that my methods are ideal, I only know that compared to different light schedules they give me more final total weight in a shorter time. There might be more efficient way but nobody in this thread has suggested any. I think Spurr is suggesting something like putting a filter over the lights or something like that but it sounds like he hasn't actually done it himself, so no real experience unless I missed it.

Your methods are not ideal, I have told you this a few times. Your use of 24/0 is better for you because using 18/6 would mean less DLI because you use low wattage lamps and/or low irradiance due to distance from canopy.

The goal is to pack in more light in fewer hours to (at least) equal the light (DLI) from 24/0. That is how you are able to have a night, and have highest rates of growth.

You can not say that 24/0 gives you more yield unless you account for the other major factors that affect yield. Please stop writing it as a fact that 24/0 is better for yield. See this post of mine explaining why you can't claim what you do with any reasonable degree of correctness: https://www.icmag.com/ic/showpost.php?p=3999050&postcount=48

I told you a few times how to grow with a night-period while providing the same light per day (i.e. DLI). Sadly, you admitted you only "read a few lines" of all my posts, no wonder you don't understand and think I haven't given you all the info you need!

Do this so I can help you provide the same, or very close to the same DLI with less hours per day of light:

Measure the irradiance at your canopy with a good light meter. Take measurements every 3 inches by length and width and then average them. For example, if you have a 1'x1' canopy you would take 16 measurements. Once you tell me what you used to measure the light (Lux, lumens, etc) I can help you convert that into DLI. Then we would calculate backwards from DLI using shorter day light hours with higher irradiance to find the same DLI. Then you would provide the higher irradiance for a shorter time, enabling you to provide a night time.
​

I am not suggesting putting a filter of the glass in this thread, that is something I am working on to reduce intracanopy red:far-red ratio to reduce stretch. It has nothing to do with this thread.

 

[spurr]

Fwiw: Light to a plant is like weights to a body builder. The more weight then the more muscle. Just makes sense doesn't it.

There is a point of diminishing returns, i.e. "light saturation". Too much light at one time, or over the whole day, is bad. The former can cause "midday depression of photosynthesis" due to photoinhibition, among other ills to plants such as leaf bleaching, photorespiration, etc; the latter can also cause photoinhibition as above. See this post of mine for info on why too much daylight is not good: https://www.icmag.com/ic/showpost.php?p=3999050&postcount=48

For cannabis we should not exceed 1,500 PPFD (umoles/meter^2/second) and ~46-48 DLI (moles/meter^2/day), otherwise rate of photosynthesis will be reduced, as will growth and biological processes.

To continue with your bodybuilder analogy:
More weight doesn't necessarily mean bigger muscles. Training more than 4 days a week is bad for muscle development, and that is why bodybuilders (the smart ones) don't workout more than 4 days a week; that is analogous to DLI for plants. And if a bodybuilder tries to lift too much weight at any one time he can hurt himself and hurt his progress; that is analogous to providing too much light for plants at one time (a la PPFD, Lux, lumens, etc). Also, sleep is when the body builds most muscle, so if a bodybuilder doesn't sleep he won't get as big and strong as he could...just like plants

Do plants need sleep? Yes and they'll get 12 hours of it every night in the flowering cycle.

Your logic is flawed, plants need night every day to be the best they can be.

 

[HydroJen]

Dear Spurr,
Your posts are long winded. I feel like I'm doing homework. I can't tell if ur speaking truth or BS cuz I keep dozing off in the middle of ur big-worded rant. Probably all true, but my desire to learn has died.
Sorry to b blunt, it's gone on for many pages
-H

 

[spurr]

HydroJen,

I don't take offense, and if you think my posts are long you must not do much reading! My posts are not long, but they are longer than the average post here at ICmag and other forums where people feel they don't need to explain things in detail. I am trying to help teach you gals/guys, and I don't use slang, so my posts are longer than the average bear.

BTW, when is the last time you read a newspaper or a book? It's a sad truth that on average most people do not read a single book per year!

It's worth your time to read and absorb what I wrote, esp. the post to Japan below, it's only 15 sentences (the rest is references you don't need to read if you don't want to): https://www.icmag.com/ic/showpost.php?p=4002179&postcount=132

The take home for you:

24/0 is not good for plants for a myriad of reasons, the goal is to pack in lots of light (over a whole day) in 16 to 20 hours. For people who use 24/0 they should find the DLI and then provide that same DLI in less hours, say 20/4 or 18/6.

Short enough for ya?

 

[guambomb813]

Dear Spurr,
Your posts are long winded. I feel like I'm doing homework. I can't tell if ur speaking truth or BS cuz I keep dozing off in the middle of ur big-worded rant. Probably all true, but my desire to learn has died.
Sorry to b blunt, it's gone on for many pages
-H

Without homework how do we learn? I do my homework before I go on vacation, out to new restaurants, many things, may be just me i'm not sure but I assume that to most of us doing extra homework to better understand our girls is definitely worth the work.
Although I do agree with me having little knowledge of most of what spurr speaks it seems to be difficult for me to follow along...i end up re-readin most of his posts and a few google searches to kinda better understand.
But for me that's more desire to learn something that I do not know. I'm following along easier and easier as I research and read up on it from alternate sources I've searched for and there definitely are ties between what spurr talks about...but do I understand fully? nope lol not close...but better. whether it's 100% truth in terms of cannabis during veg does not matter, we can do homework and determine its worth, we owe that much to our girls

-.-

 

[spurr]

^^^ 1,000% agree! I too was in your shoes a few years ago, I taught myself most of what I know due to my access to great Universities. You are correct that to fully absorb what I wrote it means re-reading a few times, and thinking, and reading the references I posed on page 9, and doing google searches too. FWIW, using 'google scholar' is a great resource vs. plain old google (as is SCIRUS scientific search engine).

The more people re-read what I wrote, and consider it over a few days, the better their understanding will become. The topics I am writing about are new the cannabis world, so there is a learning curve that must be surmounted. I think of it like when we all knew nothing about plants, we had to read, read and read to get to where we are...the learning is a lifelong process.

And like I wrote, if anyone has specific confusions or questions I am very willing to break it down more. But I can't break it down into more simple terms/concepts unless people tell me specifically what they are confused about or have questions about...I am here to help, I get little new knowledge from cannabis forums, I post at cannabis forums to help others, not myself.

 

[TriWingGirl]

How much difference will it make

How much difference will it make

I have just started using 24/0 on some new seeds.

My question is will they really grow that much faster. reducing my grow time? By how much? It would usually take 3-months at 18/6 to get them to flowering size. it would take a month just to get them to the first transplant. i only transplant 3 times. Cup to 1 gal, to my full sized pots. this can take up to 90 days. i go by the root development.

How much will 24/0 cut off this time and how much better growth can i expect.

Anyone done the experiment, know the answer to this?


Wait i found spurs posts. now somebody answer my question. i get that it should be 20/4 but how much time will this save?

 

[spurr]

I have experimented and it's not as simple as hours per day. No one can tell you how much faster your plants will grow because growth is affected by many factors. You need to tell us how much light your plants are getting, then we/I can find the total light per day under various light regimens, that is what makes them grow faster. Do you have a light meter?