Flowering Light Cycle for Marijuana

The Flowering Light Cycle is the cycle you set your High Pressure Sodium Lights on to bud your marijuana plants. There is a basic light cycle and a more experienced growers light cycle for flowering and harvesting marijuana buds. In order to become successful with indoor marijuana growing, you need to know what light cycle to set your grow lights on as well as how many hours a day and how often they come on. I will show you a light cycle that will save you 50% of your production costs while gaining 30% more production, as well this advanced light cycle will cut your vegetative and flowering time by 25%.

Basic Light Cycle for Flowering Marijuana

The most common and basic cycle to set your high pressure sodium lights on for marijuana flowering is the 12 on 12 off cycle. This 12 hour light cycle is the maximum amount of light you should ever give your marijuana plants when they are in the flowering stage, producing marijuana buds. Anything more than 12 hours of light will signal the plant to continue growing in the vegetative stage, not allowing the plant to bloom and flower buds. I prefer to run my bud lights or flowering stage lights at night when the temperature is cooler for the indoor garden. If you are growing illegally, you may want to consider putting your lights on from 6pm-6am as the electric company employees do not work those hours and will not ever see your electric meter spinning at a fast rate.

Advanced Flowering Light Cycle

This advanced light cycle will save you time, money and increase overall production by up to 50%. This flowering light cycle is based on plants that are a 9 week flowering strain. Heres a breakdown of how you should set your timers for your HPS lights in your flowering or bud room:

Weeks 1-2: Set your timer for 11 hours on and 13 hours off.
Weeks 3-4: Set your timer for 10.5 hours on and 13.5 hours off.
Weeks 5-6: Set timers on for 10 hours and off for 14 hours.
Weeks 7-8: 9.5 hours on and 14.5 hours off.
Week 9: set timers to 9 hours on and 15 hours off. this is the final week of flowering and you should be “flushing” your plants to remove all chemicals and nutrients from the roots.

This is the best and most efficient way to set your timers for the Flowering Light Cycle.

How to Set Up a Grow Room

Share your love

122 Comments

  1. hi,how are u all?x im a newny to this but know very lil i got fruitflies iv dun all thee trika ,x even tried cutting ov an onion?.worked thok, but cld sum1 tell me when will i see the firstsigns of sex it been growing for 7 qwwks but is 22 cm and bushyxthanks 4 any help [email protected]

  2. yes i’am wondering if those times for the flowering cycle are right or did they get mixed up seems more light should be used for bigger buds can you let me know ty mark

  3. My flower room has been on 12-12 during the day, but I need to change it to nights. What is the best way of going about this. I have perpetual flowering, so in between cycles doesn’t work as there are no in between cycle times.

    • Thanks. Just to verify, I simply kept them in the dark for 24 and will turn on the lights to start the 12-12 up again this evening. Just hoping I don’t get seeds from the 24 hours in the dark for the one day!

    • u wont get seeds from the one day.. if your timers were on from 6am-6pm (mornings) all you need to do is let the light stay on after 6pm and then program it to come off at 6am the next day. then after that they will be on new schedule.. one day of “re-scheduling” them will not hurt anything

  4. Im new at this how long after i plant the seed do i put light and how long then i start 12/12 or whats the quickest way to harvest

    • watch my videos! light is needed immediately. depending on the strain and how big you want them will determine when to start the flowering.

Leave a Reply

Your email address will not be published. Required fields are marked *