How long to run lightslights

how long do u run lights on autoflower 24/7 or on a timer

Hey @Lnnicholas , Welcome to the forum.
I do 24/7 for the first week and then 18/6 after.
There are some who do 24/7 the entire grow.
Some do 12/12 all the way.
I find the 24/7 keeps the stretch of the seedling down and then 18/6 gives the best growth.



Autos need some rest.

I have used two light schedules 18/6 (18 hours ON/6 hours OFF) and on latest grows 20/4. I see no difference between the two; but the farmers (yours truly) gets better rest using 18/6.


Welcome to the forum!!!

ALWAYS remember: Growing is learning!!! :+1:


Look into DLI - “ Daily light integral describes the number of photosynthetically active photons that are delivered to a specific area over a 24-hour period”

Nicky has a great post started, check it out here.


ok , i have one room, plants are 3 weeks apart, 4 plants always, one light system 3 lights,one vent, whats best for my system

I would do 18/6. Autos seem to do well with that.
Sometimes you get one that wants to delay flowering and you night have to go to 12/12 to get it to flower, but that wont effect the other plants.
As @Dave101 said if you want to get more scientific you can calculate the best schedule. Check out the link he posted.

i even dry in same room. this is my first system. im 62 and growed in my 20s, autoflowering is my new try with that system for continual smoke


Pretty much the same here. 62 and started growing again a couple years ago.
I started with autos but switched to photo period plants, Autos can be monsters or runts and its unpredictable. Most will do you right. Depending on your needs the autos may be just what you need. They typically do finish up earlier than photo periods.

You dont dry in the tent tho right? You should dry in a place out of direct light.

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What is photo plants, old school drying in brown grocery bag hanging plants in them in same room for moderate heat

Can move outside room

Plants that will not flower until the days are shorter…12/12
Autos flower no matter what the light schedule is,
Photo period plants will not flower until they get only 12 hrs of light.
Sellers usually just call them Feminized seeds.

So like old times ,regular plants my same system just move to a new room and cut lights back to 12/12

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As someone who grows strictly autos (until this next grow) my. Suggestion is to learn DLI.

Run your lights at 24 hr straight for the first 2 weeks as with autos or photos.
After that I prefer to run a 20/4 as do most auto gurus.

Of course your light intensity is just as if not more important than your lighting scedule BUT if you have a quality auto genetic from a good breeder the amount of auto genetics in the plant will benefit you running a longer daylight period.
The reason is that these genetics come from areas in the world where the majority of the day if not all the day is “lights on”, this has over time let the plant adapt to its environment. Meaning functions that would normally be completed Durring dark cycles with photo plants will instead happen Durring daylight hours.

Two flip sides of this coin are, plants still benefit from a rest period as they still have photo genetics bred into them and this has been noticeable from those that have run 24hr by poorer plant health potential.
A plant can only absorb so much light, this is why DLI is so important.

Any questions feel free to ask by tagging me at @Nicky

Of course this is the information that we have been able to gather from sharing knowledge, theorys, growing experience, etc. There are no studies out there with autoflower genetics to my knowledge.

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What lights do u use and wattage

What is DLI

Look above at post #3 a link is there for explaining DLI.

Half of my lights are hlg and half are king brights.

Wattage depends on size of area.