Alternative light cycles

guardogz

Member
well i d like to try 8/12. this would work for 6 days. then on the 7th run just a one day cycle(10/14, 8/16 or ?) less options w the analog timer
 

BobCajun

Well-Known Member
I've been using 8/16 for almost a year. I started playing around with 6/18 but found 8 hrs to be the sweet spot.
I have a 37 page thread on here about it and have said I won't ever use 12/12 and everyone thinks I'm nuts. I'm just glad I'm not the only crazy one.
Someone mentioned this idea in my thread a year ago. I think running three crops off one light makes up for the percentage of lost yield.
Having someone else saying the same thing makes me feel a lot better lol

How big of an op do u have running 8/16 times 3?
I find it amazing that you haven't noticed significant potency drop. There's an article around where they found that potency with 10/14 was half what is was with 12/12. 8/16 would have to be even worse. I guess it must be potent enough, if people like it. Would be interesting to see test results for it though. Come to think of it, I read about a particular strain requiring 8 hour days to ripen, so maybe it's enough.
 

torontoke

Well-Known Member
I find it amazing that you haven't noticed significant potency drop. There's an article around where they found that potency with 10/14 was half what is was with 12/12. 8/16 would have to be even worse. I guess it must be potent enough, if people like it. Would be interesting to see test results for it though.
I'm a lic med patient and so are most of my family members.
We all buy lab tested meds that are all 15-20plus percent and I'd say my last harvest was hands down the most potent I've had in years.
I wish I could get a nug tested too just to know myself but considering that I've been smoking the shit for 20 years believe me I can spot low potentcy from the first exhale.
I've learnt a lot from this site but I think the most important thing I've learnt is don't believe everything u read.
 

BobCajun

Well-Known Member
I'm a lic med patient and so are most of my family members.
We all buy lab tested meds that are all 15-20plus percent and I'd say my last harvest was hands down the most potent I've had in years.
I wish I could get a nug tested too just to know myself but considering that I've been smoking the shit for 20 years believe me I can spot low potentcy from the first exhale.
I've learnt a lot from this site but I think the most important thing I've learnt is don't believe everything u read.
Interesting. So how much weight did you get with two 12/12 crops vs three 8/16 crops? It can't be a full 50% more, maybe 25%. I guess any increase is a benefit, as long as it's as dense and potent.
 

torontoke

Well-Known Member
Running 8/16 I found we got 75-80% of a 12/12 yield.
I haven't done 3 8/16 at the same time.
The thinking came from well losing 25-30% of your yield wasn't worth the energy savings and then someone else suggested that while only using the light for 8 hrs u could then use the same light for two other harvests.
I only thought of it in a hypothetical sense until @qwizoking just said that's what he does.
I was planning to set up an area this summer to try it out and weigh the numbers after the fact.
But if 12/12 yielded say 1000 grams
Two harvests 2000grams
8/16 yielded 800grams
Three harvests would yield 2400grams so in theory your up 400grams vs 12/12.
 

BobCajun

Well-Known Member
Running 8/16 I found we got 75-80% of a 12/12 yield.
I haven't done 3 8/16 at the same time.
The thinking came from well losing 25-30% of your yield wasn't worth the energy savings and then someone else suggested that while only using the light for 8 hrs u could then use the same light for two other harvests.
I only thought of it in a hypothetical sense until @qwizoking just said that's what he does.
I was planning to set up an area this summer to try it out and weigh the numbers after the fact.
But if 12/12 yielded say 1000 grams
Two harvests 2000grams
8/16 yielded 800grams
Three harvests would yield 2400grams so in theory your up 400grams vs 12/12.
That could really be helpful in large commercial facilities where power adds up. You get 40% more for the same power.
 

torontoke

Well-Known Member
That could really be helpful in large commercial facilities where power adds up. You get 40% more for the same power.
Very doubtful that any commercial grower even thinks about altering a system they already consider working. My intention was always energy savings on a small scale since I only grow for myself
That's why I was curious to the size of qwizo's op.
 

qwizoking

Well-Known Member
i have 6 grow houses right now..

my biggest "client" wants 20lbs every 2 weeks, next 5lbs a week..


its spread out, partly because i really don't know much about elec. and i like multiple spots, i feel safer from laws as well as criminal types.. even riu makes me paranoid though



when i first mentioned this, i said its purely (imo) for a commercial op, its not the best way to get connoisseur smoke. but more weight.. and lowers cost to produce, even more. my bud at 12/12 sits between $.38-.27 per gram depending strain yield etc . i havent figured up all the logistics of 8/16 yet. but i know its less, im hoping to knock that top number down to the bottom one; 30%..its not alot but
but id rather not go into something uncertain. ill have a better idea as this year progresses. maybe 6months or so
 

churchhaze

Well-Known Member
8 hours of light will definitely reduce yield as it significantly decreases daily light integral. In order to keep DLI up, you'd have to use higher intensity lighting. In my opinion, it's better to increase DLI through extra hours than it is through light intensity.

You could just as easily save light by having fewer lights spread out over more area. (less intense light)

I flower under a 13/11 hour schedule, with a 730nm pulse after lights out. This allows me to get an extra hour of light per day and 1 less hour of darkness meaning a faster rate of leaf starch->sugar conversion at night. (allowing faster respiration) Me and other people using 730nm sleep pulses have all been reporting an extra harvest per year from flowering finishing a few days early.
 

churchhaze

Well-Known Member
The longer a night is, the slower the leaves will break down the starch they have reserved in their chloraplasts from the day. The plant remembers previous night lengths and adjusts it's rate of starch->sugar conversion so it runs out of starch when the night is over. That means if nights are getting longer, the leaves will decrease the rate at which they use their stored starch so that they can make it to lights on without going into starvation mode.

(this is one reason using longer nights toward harvest won't affect the dry/cure. It will still accumulate the same amount of leaf starch even with longer nights. It will just use it slower)
 

BobCajun

Well-Known Member
The longer a night is, the slower the leaves will break down the starch they have reserved in their chloraplasts from the day. The plant remembers previous night lengths and adjusts it's rate of starch->sugar conversion so it runs out of starch when the night is over. That means if nights are getting longer, the leaves will decrease the rate at which they use their stored starch so that they can make it to lights on without going into starvation mode.

(this is one reason using longer nights toward harvest won't affect the dry/cure. It will still accumulate the same amount of leaf starch even with longer nights. It will just use it slower)
What do you use for IR? Doesn't seem to be a convenient source to buy by just walking into a store, unless you use Ed Rosenthal's suggestion of incandescent bulbs with black paper over them, which actually sounds like a recipe for a paper fire.
 

churchhaze

Well-Known Member
What do you use for IR? Doesn't seem to be a convenient source to buy by just walking into a store, unless you use Ed Rosenthal's suggestion of incandescent bulbs with black paper over them, which actually sounds like a recipe for a paper fire.
730nm leds attached to a flat aluminum bar. It doesn't need to be very intense as 730nm isn't very well absorbed by chlorophyll (it reflects off the leaves and transmits through)

An incandescent with a theatrical filter over it would work, but actually seems more of a hassle at this point.

This is 1 of my sleep lights (or whatever you call it). The heat sink on it is overkill.. you could get away with just a flat aluminum bar. (my like my other one)

IMAG0182.jpgIMAG0181.jpg

The wall it's hanging on is not a grow room ... just a place I hung it to take a picture.
 

BobCajun

Well-Known Member
730nm leds attached to a flat aluminum bar. It doesn't need to be very intense as 730nm isn't very well absorbed by chlorophyll (it reflects off the leaves and transmits through)

An incandescent with a theatrical filter over it would work, but actually seems more of a hassle at this point.

This is 1 of my sleep lights (or whatever you call it). The heat sink on it is overkill.. you could get away with just a flat aluminum bar. (my like my other one)

View attachment 3590108View attachment 3590112

The wall it's hanging on is not a grow room ... just a place I hung it to take a picture.
So nothing you can just get in a store then huh? Maybe a small infrared heater. I wonder if that's in the near IR or too far.
 

Cornfed Dread

Well-Known Member
I've been using 8/16 for almost a year. I started playing around with but found 8 hrs to be the sweet spot.
I have a 37 page thread on here about it and have said I won't ever use 12/12 and everyone thinks I'm nuts. I'm just glad I'm not the only crazy one.
Someone mentioned this idea in my thread a year ago. I think running three crops off one light makes up for the percentage of lost yield.
Having someone else saying the same thing makes me feel a lot better lol

How big of an op do u have running 8/16 times 3?
I also Wil never flower 12/12 again . Been veg 16/8 for longtime, and have fixed to a10.25on/13.75hrs off flowering. Noticed different expression s from plants ,faster finish, with no loss of yield etc. Sativa an sativa dom hybrid s respond the best I ve found. Some indica don't like as much so I put them in a 11/13 an yes that 3/4 hr makes big difference. Check my latest post in my journal my Phoenix Fire #1 blew my mind how it responded to that lighting hrs an some other variables been messing with.
 

BobCajun

Well-Known Member
Oh I know how you could get an IR light in a store, in the photography department for use with IR cameras.
 

churchhaze

Well-Known Member
Oh I know how you could get an IR light in a store, in the photography department for use with IR cameras.
It can't be any IR, it has to be 730nm. Far-red looks the same as regular red. If it's invisible, it's not going to work. Be careful with far-red btw. Your lenses will focus it onto your retina and could cause it to burn, even when it looks dim. (1W of far-red looks dimmer than 1W of red, but 1W is 1W)
 
Last edited:

BobCajun

Well-Known Member
It can't be any IR, it has to be 730nm. Far-red looks the same as regular red If it's invisible, it's not going to work. Be careful with far-red btw. Your lenses will focus it onto your retina and could cause it to burn, even when it looks dim. (1W of far-red looks dimmer than 1W of red, but 1W is 1W)
But Ed Rosenthal said you can use a light bulb with a black covering (he said paper but that would burn). Maybe Ed was just wrong, who knows. I wonder what the spectrum of an IR photography light would look like. Here's one that's 730 nm.
 
Last edited:

BobCajun

Well-Known Member
I should add here that yeah, Ed was wrong about the black paper. IR doesn't become invisible until 950 nm. 730 is actually a visible red.
 

redcaes

Member
A lil off topic but has anyone ever tried triggering flowering with 12/12 and and then just leaving the lights on 24/7? Is this possible? I mean from what i understand veg and flowering are triggered by sleep cycles. So if you don't let it sleep til it's done will it completely finish it's flowering in one really long ass day?
 
Top