Grow lights are an excellent tool for fulfilling light necessity when it comes to growing crops or plants indoors in a marijuana grow tent, but they can also be harmful to the plant if you’ll overexposing them.
So, once your grow lights are already set up, it’s important that you know how long to keep grow lights on plants.
You always need to make sure that the plants you are growing indoor are still getting enough light to make sure that they grow nicely.
What Is A Quantum Board?
The term “quantum board” was first introduced by Horticulture Lighting Group (HLG for short), a relatively new supplier of LED grow lights. It referred to a new style of light where a large number of small LED diodes are affixed to a flat board.
Quantum board from the front
The diodes are arranged in rows that are run in parallel configurations by a high-powered constant current driver. There are now many different boards available from multiple manufacturers, with varying configurations.
The primary board HLG is currently using is the QB288 V2. It features 288 Samsung LM301H LEDs, which are some of the most efficient LEDs on the market. Two variants of this board replace 16 of the Samsung diodes with deep red Osram diodes, or with blue diodes.
HLG has always used top quality components, like Samsung LED diodes and Meanwell drivers. This focus on quality components is one of the reasons quantum board became so popular.
These days, many brands make quantum boards and some of them use the same components as HLG. Others swap them out for cheaper alternatives, in order to keep costs down. All are still considered quantum boards though. We’ll take a look at each of the primary manufacturers below and see how they compare.
Why your seedlings aren’t getting enough light?
Light is the number one underestimated factor of growing, even at the seedling stage. If seedlings don’t have enough light, they grow more slowly and can become leggy. Overall, growers who do not give seedlings enough light have longer crop timelines and higher rates of seedling mortality.
Why do growers mistake the level of seedling light?
They don’t have enough lighting.
They place lighting too far from seedlings (bad coverage).
They don’t leave lights on long enough.
Usually, these problems are easy to fix: add lights or adjust your seedling light schedules! Here are some general seedling light guidelines to speed up production and save you money on seeds.
How To Measure Light for Plants?
Let’s quickly define PAR and PPFD. PAR (Photosynthetically Active Radiation) describes the portion of the visible spectrum that plants “see” and use for photosynthesis (400nm-700nm). PPFD (Photosynthetic Photon Flux Density) measures the amount of light (PAR) a plant receives over time. PPFD represents the light density a plant receives over time and is measured in micromoles [of photons] per square meter per second (1).
A way to visualize PPFD is to imagine the sun is “pouring” light onto the plant leaves. As the sun pours light onto the plants, their leaves are collecting the energy. PPFD is the measurement of the amount of light (photons) the sun “pours” onto the plants over time. PPFD is an important metric because it helps growers accurately measure the light intensity for photosynthesis at the canopy level. It is also important because lights placed too close to the canopy can cause burning, bleaching, stunted growth, or discoloration.
How long should I keep LED Quantum Boards on my seedlings?
This gives you four situations.
1) If the cost of real estate is higher, then you want to move things through your space quickly. This means that you will be paying for more hours of light (18 or so) to move crops along.
2) If the cost of electricity is higher but you have plenty of space, then you’ll want to reduce lighting a bit (12 or so hours). This means that your crops will grow slower.
3) If both costs are equally high like they are at our farm here in Laramie, then you’ll find a balance. We give our crops about 14 hours each day.
4) If both costs are equally low, then go ahead and run them fast, at about 18 hours a day. (Just remember to give crops everything else that they need as well, like airflow and CO2, or they won’t be able to use all that light.
Where Should Grow Lights Be Located?
For seedlings, LED grow lights should generally be mounted between 24-36 inches above the plant canopy – however, this depends on the power (wattage) of the light source. Locate your LED grow lights at the furthest distance from the seedlings (~36”) – this keeps heat and light intensity levels lower and helps prevent seedlings from drying out. Once roots have been established and sprouting has started, the lights can be moved closer (usually within the first 2-3 weeks).
In the vegetative stage, 240W quantum board LED should be between 12-24 inches away from the top of the canopy. During this stage, more light is needed for photosynthesis, so the light source should be located closer to the plants.
As the plants progress through the flowering stage, their demand for intense light decreases. The top leaves of the canopy should be between 18-24 inches from the light source to produce flowers. It is at this stage that the plants increase in height and grow fruit. Depending on lights and how you want your crop to grow, it is not necessary to change the height of the lights during flowering, especially if you do not want taller plants.
How Far Should LED Grow Lights be from Seedlings?
At the very early stages of growth, seedlings are delicate and require less light intensity. This means you do not want to turn up the intensity too early as the seedlings will thrive with a far gentler approach. Depending on the size of the light, it is safe to keep grow lights located somewhere between 24-36 inches from the top of the soil.
Conclusion
Growing plants indoors will really require proper planning and equipment. If you want to be successful in growing crops or plants indoors, you’ll need to really invest your time and effort.
It’s not easy to establish a routine when it comes to the light exposure of the plants you are growing if it’s not automated so you really should plan accordingly.
The best thing that you need to do first is knowing what type of plant you have so that you could cater to its needs.
Light intensity and time exposure are just a few crucial things to keep in mind when growing plants so make sure that you have yourself ready! A full spectrum LED grow light can be a good choice!
Growing plants indoors can be an enjoyable hobby and even provide a living. It shouldn’t be stressful and hard. Knowing what things to consider is always a must. Enjoy growing indoors and good luck!