changing light periods?

soldier coleone

Active Member
and yet again another noob question i live in central cali where it gets kinda cool during the nights in the winter like between 40 and 50 somewhere around there. my leaves have been curling during the night because of the cold weather. and of course i have my hps on during the day i already have it on 12/12 as of today it has been flowering for a week my question is could i change the light period too be on during the night to fight off the cold weather or would it hermi the plant my strain is also bubba kush and of course it is my first grow. thanks for any help in advance
 

Hilo

Well-Known Member
i belive so man, you have to leave the plant in the dark until ur desired time you want to change to.
 

soldier coleone

Active Member
so my time period that my lights turn on is 4am and they turn off at 4pm i just leave em in the dark for 24hours then switch the timer to say like 9pm to 9 am so on and so forth
 

frmrboi

Well-Known Member
so my time period that my lights turn on is 4am and they turn off at 4pm i just leave em in the dark for 24hours then switch the timer to say like 9pm to 9 am so on and so forth
you got it, extra dark is no problem when time shifting or power outages.
 

Hilo

Well-Known Member
do the plants grow more with lights on or off frmrboi?

do they just collect energy with the lights on then spend it all in the dark to grow?

dont mean to hijack, just curious.
 

soldier coleone

Active Member
alright here is another question maybe im making it too complicated for myself im gonna get ready to shut the lights off at 3pm actually in a half hour from now. and friday at 3pm my 24 hr period will be up but i want my lights too come on at 9pm so shit thats like 30hrs. with the lights off. and another question do the leaves curl when they are cold or is it a defenciency. i think im gonna post some pics n a few to show you guys for a better diagnoses
 

Hilo

Well-Known Member
alright here is another question maybe im making it too complicated for myself im gonna get ready to shut the lights off at 3pm actually in a half hour from now. and friday at 3pm my 24 hr period will be up but i want my lights too come on at 9pm so shit thats like 30hrs. with the lights off. and another question do the leaves curl when they are cold or is it a defenciency. i think im gonna post some pics n a few to show you guys for a better diagnoses
some pics would help, mine didnt curl and it got into the low to mid 30s a few nites in a row. if it takes 30 hours of dark to get where you want to be, then 30 hours it is brother.
 

frmrboi

Well-Known Member
do the plants grow more with lights on or off frmrboi? do they just collect energy with the lights on then spend it all in the dark to grow?.
it's a unique plant in that it will grow in both light and dark that's why 24 hours light during veging will get you to flowering size the fastest.
(copied and pasted)
Most green plants are classified as either C3 or C4 which represents how carbon(C) is used during photosynthesis.
C4 plants temporarily store carbon dioxide(CO2) over the dark period to use for photosynthesis during the day. C4 plants slow down photosynthesis once the stored CO2 is used up and they need to gather it from the air. Which is why trees slow down photosynthesis in the afternoon even though the sun is still bright. This does NOT apply to cannabis.
C3 plants(cannabis/veggies) gather CO2 only during the light period when they are photosynthesizing. During the dark period these plants only use oxygen for their metabolic life processes. They don't uptake CO2, nor do they use it. As soon and as long as the light is on, C3 plants gather and use CO2 for photosynthesis.
C3 plants also have the ability to use higher concentrations of CO2 than what is found in the air. If the light is bright enough and the plants have sufficient nutes, their growth rate will accelerate from it(2000ppm vs. 400ppm of CO2), which increases yield. They can do this continuously, wihtout a dark period throughout the vegetative stage.
The dark reaction is a process of photosynthesis that takes place in both darkness and light. It uses ATP and NADPH molecules that hold energy absorbed from light to break apart CO2 into it's base components. Because it's called a dark reaction and can occur in the dark, some people(Jorge) have said darkness is needed for this to occur. This Is Not So.
Again people get anthropomorphic with their plant needs. People need rest, so plants must too. This is false as well. Light means growth. Scientifically. Although 18/6 will shock your plants less when you switch to 12/12, it's a personal choice whether you would rather sacrifice a little growth for a quicker adjustment or less photo confusion. If you want to save money or energy that's a personal choice too. Do what you need to do to make your growing scenario work.
 
Top