How many hours of light do you need for a grow tent?
Although different types of plants might be different, in general, most seedlings require 14-18 hours of light illumination for growth. It is different from starting seeds, to germinating, most of the seeds do not need light. But plants like Begonia, Primula, and Coleus, need light to germinate their seeds.
Vegetative
The vegetative light cycle of cannabis is when plant growth truly takes off. Much like a human adolescent, the plant will achieve most of its vertical growth during this time. Lasting between 3 to 16 weeks, the vegetative stage requires full-spectrum light for 18 hours and 6 hours of darkness.
' plants do require a daily respiration period of at least 6 hours per day (for seedlings) and ideally 8-10 hours for more mature plants. Therefore we do not recommend providing more than 14-16 hours per day of light, even if you are growing long-day-loving varieties and trying to induce flowering/fruit from them.
The 18/6 light cycle and the 12/12 light cycle
The second stage of marijuana growth requires much less light and more darkness. The optimal light cycle used is 12 hours on, 12 hours off. This 12/12 light cycle is referred to as the Flowering Stage.
| Grow Room Size | Square Feet | Veg Wattage |
|---|---|---|
| 1' x 1' | 1 | 20 watts |
| 2' x 2' | 4 | 80 watts |
| 3' x 3' | 9 | 180 watts |
| 2' x 4' | 8 | 160 watts |
After the plants reach the final stage of grow, and get to their full size, we do not need to use the grow light that much. Even though they've already stopped growing, you shouldn't ditch the grow light completely. A fully-grown plant would still need about 12 to 14 hours of light per day.
Increased light duration allows the plant to make sufficient food to survive and grow. However, plants require some period of darkness to properly develop and should be exposed to light for no more than 16 hours per day. Excessive light is as harmful as too little..
A: In general, you should not leave grow lights on 24/7. Plants need a light-dark cycle to develop properly. It's believed that they truly do “rest” during periods of darkness, and probably use this time to move nutrients into their extremities while taking a break from growing.
Plants require periods of both light and darkness to keep their metabolism and blooming phases in balance, and when they get too much light, those patterns are disrupted. While some plants need less darkness time than others, too much light will impede any growth schedule over time.
Leave the grow lights on for 14 to 16 hours per day to provide light for the young seedlings. It's best to turn the light on early in the morning and turn it off around dusk. Your seedlings will still thrive if you deviate from this schedule.
Do buds grow at night or day?
Because bud formation starts after 7 hours of dark period, it is also wise to always maintain a minimum day length of 17 to 18 hours during the vegetative period. A dark period of 12 hours is used as a standard in cannabis to ensure a smooth flowering process.
Sativas are usually switched when they reach 30–45cm, since they grow so much during the flowering stage. Indicas are switched when they reach a height of around 100cm, giving them more time in the vegetative state. This method is designed to produce very heavy yields from a minimal number of plants.
Height of plant: Depending on the strain, plants will generally double in size during flowering. So, if 'room' height is limited, the switch to 12/12 will need to be done no later than when the plant has reached 50% of the 'available' height (remember to consider the minimum gap distance between lamp and foliage).
In your typical 4ft x 4ft or 1.2m x 1.2m tent the extract fan, circulatory fan and water or air pumps will consume between 15 to 30 watts each or about 70 watts in total. The grow light wattage to delivery a good yield will range from 400 to 650 watts, depending on the technology used.
Grow tents let you control the light, water, temperature, and humidity, so that your plants can grow faster and stronger. Weather and external factors are not a concern because you control the environment.
4' x 4' Grow Tent - Perfect for the footprint of a 1000w HID or LED grow light (4-6 plants) 5' x 5' and 4' x 8' Grow Tents - Our most popular tent sizes (4-10 plants) 5' x 9' and 8' x 8' Grow Tent - Great for a spare bedroom, expect large harvests (9-16 plants)
The light you use should come with specific instructions. But as a general guide, here's a few tips. To be effective, grow lights really need to be on for at least 8-10 hours a day. This can vary up to 16 hours, depending on the conditions.
Technically speaking, yes, you can leave LED lights on 24/7.
This is because, unlike traditional bulb types, LED bulbs give off very little heat during operation.
As an unofficial rule of thumb, many growers work on the basis that: You need 20-40 watts of power per square foot. Lower wattage LEDs of around 200 watts should sit between 12-20 inches from the top of the plant. Higher wattage LEDs of 1000 watts and above should sit between 36-46 inches from the top of the plant.
You can also extend the vegging time to get them where you want them to be before the big switch. But remember: never let your plants get less than 14 hours of light during the vegging stage unless you want to start flowering early.
How many hours of grow light do vegetables need?
Once sprouted, most vegetable seedlings and other garden plants require at least 12 hours of good light per day, along with 8 hours of darkness. However, seedlings will grow the best when provided 14 to 16 hours of light.
Like all plants, vegetables need the sun to kick-start photosynthesis. The fastest-growing vegetables need full sun—at least 6 to 8 hours of direct sunlight a day—without blockage from trees, shrubs, or fences. That's why you won't have much success if you plant sun-loving vegetables in shady spaces.
If you're a cannabis grower, you understand that vegetative plants need 12 hours of light and 12 hours of darkness to trigger the flowering stage. However, plants with naturally long flowering stages like pure sativa strains can benefit from 13 or 14 hours of darkness each day.
