Changing light cycle mid-grow from 24/7 to 20/4


I have a question. I have some G-13 autos that I am growing right now and I have been using 24hr light on. I have been reading that you should use a 20 on and 4 off for example. They have been growing for about a month now and flowering and I am wondering if I can change it from 24hr on to 20 on and 4 off, will it cause any problems like morphing etc.

still learning.


Shouldn’t be a issue just expect more vertical growth from lights being off. I personally use 18/6 after 2 weeks

Welcome to the forum.

You can change the light cycle without worrying about it at any time (with an auto.)

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Thanks for the quick reply. I’m still reading, lol. I now see that the three 12"x12" 75wat led lights from Amazon are not going to produce good buds. I had pretty good results (to me anyway) when I grew some Critical Orange Punch but no high. I’m trying not to raise my power bill and stay incognito. The plants look great and grow like crazy in my 4’x2’x50". Do you think the Horticulture Lighting Group 260 Watt V2 Quantum Board LED Kit (DIY) that you mentioned will raise the power bill so much that it will raise a flag? Maybe i’m just paranoid but I really don’t want to go to jail, lol.

is a 300w light good for starting off 4 plants if not how soon into growing should i upgrade?

You are going to want better lighting by the time you get to veg (~2 weeks from sprout.)

Lighting is one of the most important factors in growing cannabis. Make sure to stay away from the Amazon burples and buy a quality light such as HLG, Fluence, Bridgelux, or a Spider Farmer with Samsung LM301 series diodes.

A single 300w burple is barely enough for one plant. It’s probably more along the lines of 50 - 100 true watts and of poor spectrum at that.


It’s only 260 watts or a little higher. That’s less that most computers use. Many of us here run multiple HLG 260s without issue.

It’s a great light and you’ll be happy with the results.


Thanks for the info everyone. I will look into the lights you mentioned. I don’t know whether I will be able to purchase two of them though. will one work for the 4’x2’x50’’ tent? I really really want to grow the big buds, lol.

One HLG 260 is ideal for a 2x4.

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Okay. Boy, I wish I had this forum when I first started this wonderful journey I have no one to talk to about this subject. Is no question too stupid? I hope not because I will certainly have more questions. I hope this is ok.


Okay. Boy, I wish I had this forum when I first started this wonderful journey. I have no one to talk to about this subject. Is no question too stupid? I hope not because I will certainly have more questions. I hope this is ok.


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No stupid questions around here. We all started out knowing very little, and cannabis can be a challenge at times.

You will find this helpful:


I found this one: Horticulture Lighting Group 260 Watt V2 RSpec Quantum Board DIY Kit (Full-Cycle / Flower) on for $349.00 w/ free shipping. I think this is the same one. It looks like the same unit except it costs $20.00 less. Will this be okay,

I said the same thing when I started my first grow about a year ago. I bought all the wrong equipment not really knowing. And now…I feel like I took a crash course in growing, an accelerated Masters course if you would! Reading is fun when it is interesting and relevant, right? :+1: :sunglasses:

As you can see, this form is unlike others I have visited. No judgments here. The support and sharing of knowledge is amazing!

Happy growing, happy learning.

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If you buy a HLG kit you get a one year warranty, but if you buy it assembled from them it’s a three year. Just more to think about.

1 hlg 260 will probably be cheaper to run than the 3 blurples u goy going now. Ive notice that real wuick with blurples and the hlgs. Blurples are less wattage than posted in descriptions and use more energy to run the fans and what nots. I saved atleast 60 bucks a monyh going from basically 5 blurples to 3 hlg 260 xls and 4x 240 watt enfun qb boards

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The 260 you are looking for will consist of 2 QB288 V2 Rspec Quantum Boards. Make sure to get Rspec boards so that you are giving your girls the proper spectrum when flowering.

I’ve bought HLG from third party sites before and have been happy. The site I used was growerslights dot com. Good price and fast shipping was my experience, and I’ve bought a couple of 260s from them.

You will want this one (260W XL QB V2 Rspec LED Kit) I just purchased 3 of them they are $369 each you only need one (they do not charge you tax that will save you over $20)
You can always call HLG they are very helpful to make sure it fits your needs and you get what you want
It only took 21 minutes after ordering before I got a shipping notice and 5 days it was at my door. Assembled them yesterday will wire today
Best of luck to you :sunglasses:

Phone: 1-877-445-4533