Running led on 24/7, is it s good idea to dim down it to 50% during night (8 hours)?


I tried to Google the answer for this question, but couldnt find anything.

Most topics seem to be only about how much percentage you should dimmer during different stages, not if you could use dimmer during night time.

The Reason I Ask This is that Many people prefer to grow in 18/6h because They need to rest, it could stress them with lights on 24/7

So, what do you think will happen if i dim my lights only during nighttime, Will it be beneficial to my plants health/growth?

Anyone here tried this?

I would really appreciate any input about this question, even of you are not sure if you are right.

If someone have a good link about my question please share.

I mean it would be awesome if it boosted health growth.

For me it makes sense that this might be a good idea for people that let their lamps on 24/7 (during veg). Especially it you do HST and LST which stress them.

Thanks in advance, looking forward to your answers/thougts about this!

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Not sure exactly what you are asking but you mentioned light durations. We all need rest. Plants metabolize at night or during lights out. If you never give them any darkness, they never take advantage of what they do during the day. So although I use the typical 18/6 even 4 hours of darkness is better than none.

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Some people prefer lights on 24h per day during vegg.

I grow that way too now since friends tried it and recommended me to do it

In trying to Ask if my plants Will benefit from lowering the dimmer to like 50% for 6 hours and 100% the rest of the day. Instead or having it on 100% all the time?

Do you understand me now?

Cannabis plants don’t actually care about rest. There’s a study out there from GW Pharmaceuticals that ends up somewhere around this - for an 18/6 light cycle, it takes 28 days to generate a specific amount of mass.
For the 24/0 light cycle, it took 21 days to generate the same amount of mass.

For veg, there’s no reason to get fancy. Either do 18/6 to save yourself heat generation/energy costs, or do 24/0 and enjoy bigger plants faster. :man_shrugging:

Same thing is true for flowering autos. No real reason to give them dark time or a lower light intensity period.


Cannabis is a C3 plant that doesn’t need a dark period to complete all metabolic processes. It’s important to remember that there is a limit to the amount of light a cannabis plant can use.

I do but I do not agree with lights on 24 hours from experience and knowing all living things need sleep.
Regardless of dimming for night periods but still leaving the light on.

This is a choice as once again there is conflicting info online. The below is what backs up my reason if you need an outside source of info, but I have always given my plants a dark period for metabolizing what energy they produce during the day.

Everyone knows that plants photosynthesise when exposed to light. However, much like animals, they have different processes that take place during the night. It is therefore important to give your cannabis plants adequate time in the dark.

While plants photosynthesise in the day and create energy for themselves, they metabolise their stores of energy during the night. Excess energy captured during the day is not simply wasted, but converted into starch to be used in periods without light. Think of it like fat on an animal. Whether it’s essential for plants to actually metabolise this starch is not entirely clear. What is known, though (from autoflowering plants), is that cannabis plants subjected to constant light do not inherently produce better or stronger yields.


This is exactly what I have known years ago. It really sound logical and like this is how nature works.

When I did my first grow over 10 years ago I followed 18/6 because that is what i learn from the textboks. And I never question this since I thought it made sense.

So when my friends told me They dont give their plants any darkness I thought that They were joking but They didnt because I tried myself and im happy with the results.

I think we still are learning more and more about weed and the science cant perhaps explain everything so sometimes you just have to try it and see for yourself.

Its like the discussion about ”to trim leaves or not”, there is no right or wrong thing.
Its just different method that obviously works, like this method,.

And which way to do it is up to the actual grower to decide.

I understand why you like 18/6 and I think you should keep grow as you like.

As for me, I believe i dont have a definitive answer for which light schedule is the best one since I think it depends on grower, genetics and other things. All I can say is that both way gives good results. Personally i like to try new things and thats why i tried growing with lights on 24h

And I dont regret it. Just like when i tried topping, fimming and other LST or HST methods. It was against what i had come to learn but turned out it worked better then ever before. Despite the lack of science that back it up.

Experiment with it on a grow. Keep a good journal. Would be interesting to know how it goes. I could not afford the electric if all mine were on that long.


100% agreed. I was big on jars but tried grove bags and love them. Mostly cuz you put it in right and forget about it for 6 months.