Adjusting photoperiod length....

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true grit

true grit

So figured I'd toss it out there and see if anyone else is playing with this at all. I started adjusting my lights/flip flopping them a few cycles ago when i was doing vert walls of buds. At that point i had 4kw in a 10' row, so about 1kw every 2ft. This proved to be too much light for the plants and they simply could not process fast enough, the following run I did 2kw on at time for 6 hrs and then flip flopped to the other 2kw. I had no noticable loss in yield, but actually better yield and happier plants.

I started doing this in overhead once I switched but not sure I was goin to get the same yield since lights are on a 4' layout pattern. I bumped up the overall on time of the lights to accomodate.

So on to some questions- anyone else doing flip flop lights? How much direct light are you giving your plants- 6,8,9, etc hrs of the 12 in bloom? How much direct "sunlight" is actually needed to achieve the same yield with no loss and more efficiency?

How bout you outdoor growers? I did this with the assumption that no outdoor plant gets a full 12hrs of direct sunlight, they simply flower by photoperiod. its said outdo needs at least 6hr of direct light (granted its the super lumens of the sun! lol) and the rest is off light from photoperiod. I know my 4x4's overlap light and plants seem to be doing good. Anyone else? I should know after this run whether I'm getting close, but always got that question in the back of the head.
 
HydroRocks

HydroRocks

Probably not the info your looking for, but we have been doing testing with increasing the light period during flower. We are testing different strains now to see if the light period is strain dependent or not. So far we have been able to increase the light period to 14 hours with no ill effects. We have noticed almost a 20% increase in yield in some of our previous testing results.
 
true grit

true grit

Interesting and whats the idea behind adding more light to the photoperiod?

One reason we started to play with this idea was the fact of walking around grows and seeing that plants in the overlapping light area between lights and on the edge of teh room were often the healthiest, less stressed and often great yielding plants. then after decreasing direct light and getting healthier plants I was looking for most efficient. Ideally I think the most effecient would be the ideal direct light shifting on plants in a room from east to west to simulate sunrise/set.
 
HydroRocks

HydroRocks

I like your idea of shifting light from east to west. I guess there is an argument that could be made that the plants will waste energy moving itself to face the changing light source. Not sure if I agree with this theory at all really which is why we started to "dabble" with the light periods to begin with.

I am not sure of the original intent of running 14 hours of light during flowering other than just to give the plants 2 extra hours of "charging". I picked this tip up originally from a breeder who did this the last 3 to 4 weeks of the flowering period before harvest.

We have also tried some different light configurations. Currently using 2 HID's over head and then surrounding the plants with 105Watt CFL's (the CFL's are all hung vertical bare bulb style). This configuration so far has increased yields by as much as 30% over our previous light configuration which was bare bulb vertical HID's with side and bottom lighting supplied by 105Watt CFL's.

We are still currently testing and collecting data.

Cheers!
 
true grit

true grit

I don't think its as much saving the plants energy while lights shift east to west, cuz i can tell you the plants/buds don't even move with flip flopping lite, but more so to simulate the natural fade of light during the day. Regardless of what we do inside, the plants can always sense lunar cycle/direction.

What kinda HID's are you running- hps lights? I have to be honest, i really don't think i'll be getting any of these plants to yield those type of %'s more unless I give them more veg. I do like the idea of bare cfl's hangin all over the place though, i know Tex did that when he showed pix of his plants and his always looked top and sure it helped.

Very interesting hydrorocks. Not in the same direction I'm going but interesting none the less! to me this is a matter of finding the minimum needed to achieve the same. After you mentioned strain dependent (which i hadnt even thought about) i cruised around my growroom and can definitely see which strains need the full 12 and that some definitely do not...cheers to bringing an obvious thing I overlooked to the surface!!!
 
HydroRocks

HydroRocks

Excellent, I was hoping that even though we are testing for different things that the data might be of some use or of "mutual" use anyhow.

With the strains, if you know the heritage then you should be able to tell by location about how much sun they would be use to getting, genetically speaking. i.e. - plants originating at the equator as opposed to plants originating in European Mountains, or other countries.

That is "if" you can trace the heritage of your strains, and even then considering they probably have been "crossed" you would be getting a good "guess" at best.

It would be interesting to know anyhow I think to see how the data matches up to your real time findings. And I agree about finding the minimum as well and seems to always be the goal in all our testing even if its a "underlying" goal.

After several configurations we ended up with a 4oowatt and a 600watt for the over head lighting (both HPS). And then 8 105watt CFL's surrounding and side lighting. The CFL's are mixed half white and half red.

I should be able to post some numbers after this last 3rd run completes. I wanted at least 3 completed to compare and get a average.

Cheers!
 
W

wanderingwobble

Interesting. wondered about this before. Will be stickin around to see what you guys come up with.
 
dankworth

dankworth

I need to start comparing watts/ft2 and readings from a light meter. I believe peeps that can pull retarded grams/watt are often optimizing the light values hitting the plant. I saw DwD when he was Mr. Steppin doing awesome things with 4 1ks in a 10x10 space. 70 watts/ft2 of overhead seems like it is pushing it sometimes. I am thinking about hanging vert lights in the canopy, and backing the overhead up to more like 50 watts/ft2. Maybe lighting the plant all over(or as close to it as you can get) with the optimal value of light is one of the keys to best yield per light.

JK was just talking about how he made a bubba that was described as "sensitive" step right up to some high light values by foliar feeding. I am going to be playing more with that for sure to see if I can utilize my preexisting light values more effectively.
 
nangonug

nangonug

Premium Member
Supporter
I played with the lights the other way and found that my yeald ingreased about 15% on all but one of the strains I run by turning the light cycle to 11/13 and save tha hour of electricity use as well. The one plant that did not fair so well was a peak 19. it has never been a big producer but it seamed to loose about 10 percent. My plants actually seam to finish a couple day earlyer then on a longer light cyce as well. I sapose to be natue like a person should start with say a 14 hour on time and taper down the on time as the plants mature. I also keep saying Im going to try the 12 /1/12 veg light cycle but have not as of yet because I have a couple strains that are pretty sensitive to decreasing light. I have to make a seperate veg area for them and I just don't have any more room. I have talked with a couple people using this cycle with great results. Its 12 on 5.5 off 1 on 5.5 off 12 and so forth. sapose to save electriity as well as actually increase plant output. I will be trying this over the summer at least to lighten the ac load, Anyone else try this?
 
dankworth

dankworth

My first run, I had done some reading about critical dark periods.
So I ran with a 13.5 hour day.
It actually worked.
Didn't play with it much after that.
I need a test tent to experiment with that.

The flip-flop thing I have read about before.
But then you need more reflectors and lamps.
And the lamps fire up, during that time they are more dim.
I hate to say it, but maybe a light mover with half the lighting on all the time would be better than running 1/2 the lighting equipment at a time in a flip-flop.

Hydrorocks, I intend to play with a very similar arrangement, 1ks overhead and 400-750 watt lamps vert in the canopy to light the sides.
 
PButter

PButter

RUN!!!
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Anyone care to post up some pictures of their Flip or their clfs mounted in the canopy?

Neat topic, I have played with this in my head far too long but haven't had time to fiddle with the things I want to fiddle with.

PB
 
TrichromeFan

TrichromeFan

I believe rollinendough did a test with a checkerboard pattern of lights alternating on and off. Maybe check with his findings as well. Best Of luck on your testing there gritty and hydrorocks.

-TF
 
purpleberry

purpleberry

I got my lights all on one mover with 40w sqft I think I can smash 2p per light pretty easy. Each light covers 4x6 giving me %50 more canopy and my guess is pretty close to %50 increase in yeild. Much better than say someone with 6 lights in a 10x10 hoping for 10.
If you had dimable ballasts you could run half on %50 and switch it every day, Would save %25 power. 8k lights running at 6k with i bet very little loss in yeild.
I think to much credit is given for yeild per 1k , it should be per sqft. Ive had my best yeild in a 4x8 tent, becasue its 4.5x9.5 xxxl hoods cover good. My budy has 3k covering 4x10 and think theres a huge problem when he gets the same weight off 3k that i get off 2, same sqft. , Same strain, same size pots, same fert, Crappy hoods. Watts only go so far
 
dankworth

dankworth

(Regarding 13.5 hour days, responding to El Cerebro's question) I was thinking that the plant might finish faster as a result, that maybe the plant would require 720 hours of light total to finish flowering. Or that the plant would be convinced that it was the beginning of flowering the whole time because of the biological profile given to the plant from the 13.5 hour day cycle.

It is something to play with for sure. But I would want to do a small run in a test tent to determine what changed and how that might impact the flowering room as a whole. I think it is possible that there could be some variety in effects due to strain.

I have heard of people switching to 10 hour days at the end of flowering to accelerate the ambering of trichs. So maybe run 13.5 for a while, then 12, then possibly 11 or ten.

I am wondering if a 13.5 cycle would be best until flush, or best until the pk boost of the last 2 weeks of feeding.

Yeah, huh El Cerebro. I should start thinking about this again.
12.5% more light per day is 12.5% more light.

If there is no negative impact on health, and by that I mean potency, then I will need to get back on this horse.

Can't do 13.5 hour days on flip though.


I told this older professional grower about this years ago. He was an alcoholic, and it was past noon when I told him about this, so he was drunk. He did not write anything down.
I told him that 13.5 had worked, but that from what I had read, 14 hours was pushing it, and compatibility with all strains was not guaranteed or anything. But his dumb ass was drunk.

So then I hear through the grapevine like half a year later that he is pissed at me about it, because he ran a 14 hour day. And some 7-8 week indica "went 14 weeks and it still wasn't done!"
That was the first I had heard of it.

FFS someone go sell that guy some jug of some shit with a cartoon on it or something.
 
purpleberry

purpleberry

Now that i think about it and go back and figure, I would say im hitting 1lb per 10sqft. 4x4 hitting about 1.6 is dead on, Stetching the light to 4x6 should help. I think stetching out to 4x8 either by light mover or flip flopping lights over 4x4 will stretch the light to much. This is the reason every one i talk to about movers shot it down because they all put 1 mover over a 4x8 with no over lapping light.
I think if i was going to flip flop id space the hoods very close and not go under 40 watts sqft.
 
dankworth

dankworth

I got my lights all on one mover with 40w sqft I think I can smash 2p per light pretty easy. Each light covers 4x6 giving me %50 more canopy and my guess is pretty close to %50 increase in yeild. Much better than say someone with 6 lights in a 10x10 hoping for 10.
If you had dimable ballasts you could run half on %50 and switch it every day, Would save %25 power. 8k lights running at 6k with i bet very little loss in yeild.
I think to much credit is given for yeild per 1k , it should be per sqft. Ive had my best yeild in a 4x8 tent, becasue its 4.5x9.5 xxxl hoods cover good. My budy has 3k covering 4x10 and think theres a huge problem when he gets the same weight off 3k that i get off 2, same sqft. , Same strain, same size pots, same fert, Crappy hoods. Watts only go so far
I have seen 2 oz/ft2, 2/light recently. Sixty something watts/ft2. Room for improvement in yield was there.
Most I have seen was 2.4/ft2. But was with too much light per square foot. Different room a long time ago.
Theherbalizor just got 2.8 oz/ft2 with 1500 watts overhead in a 5x5 tent. So 2 kilos. 60 watts/ft2. I would have to get 2.94 per 1k to match that. Yeah right.
If you are feeling good about yourself, go look at his thread and you'll soon stop feeling like that. I don't feel as cool next to his 1.33 grams/watt.
FreshSteppin got 9.something from 4k in a 10x11 room, 9.4 I think.
And he probably had a 1' walkway in the front of the room.
So that is 1.5 oz/ft2.
I think the 2oz/ft2 room I talked about could get to 2.5 oz/ft2 w/just optimization of environment and nutrition.
But if there were vert lamps within the canopy that could efficiently light the bottoms and sides, then there could be 3+ounces/ft2 from the extra light contained within the same canopy area.

Someone besides me should get their ass to work with a light meter recording canopy measurements, oz/ft2, variation in strain, etc. so we can get a whole bunch of useful data.

FreshSteppin's pretty dialed run of 1.5 oz/ft2 at 40 watts/ft2 would be equaled by 2.5 oz/ft2 from 60 watts/ft2, if we are talking about apples to apples.

I believe Ed said 75 watts/ft2 was the point of diminishing returns. But that was years ago.
With better reflectors, ballasts, and lamps, I think sixtysomething watts/ft2 is about the point of diminishing returns these days in an optimized setting. But that is just the room I am used to seeing. I think I like 60 watts/ft2 for overhead these days.

Big kids, bigger rooms, doublestacked 1ks, 66" centers, talk about 2.something, sometimes your hear the 3 figure, guessing maybe same centers. So a 3'er in about 30 square feet gets us 1.6 oz/ft2.

People with limitations on room size probably weigh these concerns more than people with a surplus of ft2.

I am talking about plants that weigh at least half a pound here. I am not talking about sog.

Bigger rooms do get better results per ft2 with good canopy management than small rooms.
More light sources are better than less, all things being equal.
Reflectix, used correctly, can easily increase your total weight in a room by as much as 10%.

Edit- DD's claim of 33 pounds would require an average weight of 5.5 oz/ft2 for his 8x12 room.
 
El Cerebro

El Cerebro

I've been doing 10/14ish at the very end. Also been thinking of setting up magenta plasma strobe for the 3rd and 9th weeks, except for my 17wk sativas.
 
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