It is not recommended to leave your grow light running for 24 hours straight. Twenty four hours of light can prevent a plant from effectively carrying out the respiration process.
If your plant is not responding to 12 or 18 hours of light, you may need a stronger grow light or you may need to feed your plant nutrients. Also consider whether you need to adjust your grow light hang height.
WHAT HAPPENS TO A PLANT THAT IS KEPT UNDER CONSTANT LIGHT?
When cannabis absorbs a lot of light, they will constantly engage in photosynthesis. On the bright side, this will result in the maximum growth of foliage.
Yet, there are consequences as well. If your weeds are constantly exposed to light, especially during the vegetative stage, they may experience stress.
Once they get exposed to diseases, they also become susceptible to pests, and consequently, diseases and death.
DOES MORE LIGHT MEAN MORE YIELD?
While they are correct about needing more light, the way of gaining light is incorrect. You have to consider some factors including the weed strain, type of light, and growth stage.
It is possible to leave grow lights on for 24 hours, but it is still way better to set lighting times per day.
WHAT’S THE IDEAL AMOUNT OF LIGHT EXPOSURE FOR PLANTS?
During an 18 hour vegetative phase light cycle, you can produce 20 moles of light by using an LED grow light with a PPFD value of 308 micromoles (umol) of light.
To produce 20 moles of light during flowering phase, you’ll need a higher PPFD value of 462 umol from your grow light due to the shortened 12 hour lighting cycle.
If you want to maximize yield you’ll need to produce 40 moles of light per day for your plants.
To deliver 40 moles of light during vegetation, that’ll require using a grow light with a minimum PPFD value of 617 umols for 18 hours.
To deliver 40 moles of light during flowering phase, your grow light will need a 926 umols PPFD value to compensate for the shorter 12 hour light cycle.
LIGHT EXPOSURE AND PLANT CYCLES
A grower who wishes to produce plants with an abundance of blooms will inhibit that plant by exposing it to light 24 hours a day. Too much light can interrupt a plant’s natural process of growth, flowering, fruit, and dormancy.
On the other hand, 24-hour lighting can force plants to grow quickly. These plants can then transition to a more normal light/dark exposure when a grower desires the flowering and fruiting cycle to begin.
The ability to manage the life cycles of a plant with grow lights can increase the speed between crop production of flowers or fruit.
BEST GROW LIGHT FOR CANNABIS 2020
LUXX LIGHTING 645W LED PRO
The LUXX 645 LED PRO is made up of Samsung horticulture whites and Osram reds. The respective companies lead the field in LED R&D, delivering high efficiency, reliability & diode performance. The LUXX 645 LED PRO features manual and auto power adjustment. Delivering the flexibility to dim the unit down to 40% total power for lower photon intensity, without affecting the quality of the spectrum.
THINKGROW MODEL-H 630W HORTICULTURE LED GROW LIGHT
ThinkGrow is brought to you by the same company making TrolMaster controls -- currently one of the most sophisticated digital environmental controls on the market. ThinkGrow LED lights are also fully compatible with TrolMaster controllers with up to 256 lights being able to be controlled per digital channel.
FLUENCE SPYDRX PLUS LED GROW LIGHT
SPYDRx PLUS is designed for close-proximity, controlled environment agriculture, and multi-tier vertical farming environments. An average — not max — PPFD above 1,020 makes SPYDRx PLUS the perfect choice for high-DLI crops from veg to bloom when paired with a 0-10V dimmer or adjusted mounting height for desired PPFD.
FAQ
24 hours of light is not healthy for your plants. Plants need to rest too.
What if 18 hours of light isn’t enough for my plants?
If 18 hours of light isn’t enough for your plants and you want to run your grow light for 24 hours, you need to buy a stronger grow light. You can run the stronger grow light for fewer hours, allowing your plants time to rest.
How much light does my fruit, vegetable, or cannabis plant need?
Fruit or vegetable bearing plants, including cannabis, typically need between 20-40 moles of light per day. That translates to a grow light that emits between 460 and 925 uMols of light per second.