Visible light between 400 and 700 nm is absorbed by plants, which convert CO2 into glucose and oxygen. The plant’s cellular structure influences the amount of absorption at each wavelength. The total quantity of photons absorbed in a day is what’s known as the „Daily Light Integral.“ DLI and PPFD values for vegetables and plant species are known.
Valuations for various plant species.
CO2 and water are converted to oxygen and glucose in plants using visible light with a wavelength of 400-700 nm. The plant’s cellular structure impacts how much light it can absorb at each wavelength.
Using the Daily Light Integral, you may determine how many photons are released per square meter each day. Plant growth necessitates DLI concentrations of at least 0.1 mol/m2/d. From 6 to 18 mol/m2/d, the most common plant values.
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Cannabis photosynthetic photon flux density (PPFD)
For medicinal marijuana plants, the values are PAR and DLI. To keep the plant in the vegetative stage or to blossom, it is necessary to maintain the correct light intensity times. Lighting durations should be kept to a minimum and an ideal range.
- 16 18 24
- 16 18 24
- 10 12 14
Healthy cannabis development and a copious harvest are both dependent on the right quantity of light being provided to your plants. But any light isn’t acceptable:. You need the right amount of PAR (photosynthetically active radiation) on your plant’s leaves to make it grow.
Cannabis plants suffer from light burn when the PAR level is too high. Known as „leaf burn,“ it results in yellow leaves with green veins and stems.
Light burn can be mistaken for a nitrogen deficiency, which results in yellowing leaves. A nitrogen deficit can be detected by the strength of the yellow leaf’s attachment to the stem. Both sunburn and nitrogen deficiency impact the plant’s upper and lower leaves, respectively, but the effects of each are distinct.
The daily light integral (DLI) is the most important metric to optimize when it comes to plant lighting. An insufficient DLI can reduce plant growth and yield, while an excessively high DLI wastes energy and may even burn plants. In general, the following cannabis dosage ranges are recommended:
- Stage-DLI Value
- 10-15 seedlings
- Vegetative 30–45
- Flowers 30-40
Throughout the growth cycle, the DLI should be adjusted to the plants‘ present needs.
PPFD for veg: PAR value suggestions
Aside from the number of hours your lights are on, the PAR/PPFD numbers are critical to not under- or over-using your plants.
- Adol PARS (PPFD)
- 100-300 sp.
- 500 – 1050
A note about CO2
In order for photosynthesis to take place, CO2 and photons must be present (light). Insufficient CO2 supplementation is the primary limiting factor in most cases, even with increased light. Because of the high concentrations of CO2 in the air, indoor photosynthetic activity is quickly reduced to a fraction of its original level. Photosynthetic activity and PAR increase as a result of increased CO2 levels. These CO2 numbers are what we’d like to see:
- GROWTH CO2 VALUE (ppm)
PPFD for veg: Modern grow light types
Cannabis is now being grown under HID, ESL, and LED lights, three types of artificial lighting. These lamps are commonly used by cannabis cultivators. These bulbs are „Betamax“ bulbs, which are more than a century old. Introducing the growing lamps of the twenty-first century! In the growing chamber, we only ever employ real instruction, never any pseudo-scientific data.
Growers have been using High Intensity Discharge (HID) lamps since the 1990s, when they were first introduced. The ballasts are now computerized, and the reflectors are larger and better. Growers who use high-intensity discharge (HID) lamps believe that bulb quality is determined solely by lumen output.
Even though a 315W CMH bulb is impressive, it’s also an expensive upgrade from a standard metal halide bulb. Compared to the Agro 600W NDL with Dual Spectrum HPS light, even the 315W CMH is ineffective. On the other hand, ESL lights have a lot of potential, but they can’t match HID bulbs.
In the future, LEDs, or „light-emitting diodes,“ could replace HID bulbs. LEDs are already capable of producing grass that is as good as, if not better than, that produced by a standard HID setup. For LED fans, the most important aspect is the PAR value, which stands for photosynthetically active radiation.
HID bulbs of the old school variety
While HID lamps‘ technology has advanced, the fundamental notion of growing marijuana with them has not, as an ancient hemp man put it. For growth, use metal halide, and for bloom, use sodium vapour. Dual-spectrum HID bulbs, on the other hand, may be better for autoflowering strains.
Typically, 400W or 600W HID lights are used in indoor cannabis cultivation. The height of the lamps must be equal. Blooms should be 30 to 50 centimeters above the OLH (optimal lamp height). Using rope ratchets or Easy Rolls, attach the reflector to the ceiling of your tent.
Using attachments that allow you to adjust the lamp’s height is a good idea because the plants are expected to grow. Is 600W metal halide too powerful for seedlings? That’s what I’m getting at! Hang them 60 cm apart in this case.
Experiment with light strips only if you are technically competent! Professionals use horizontal bulbs in a clean, open reflector. The larger the reflector, the more it will distribute the light over your growing area.
Glass filters, lamps, and air conditioners are costly. Cool-Tubes are only suggested for tiny indoor crops due to their poor reflecting capabilities. Plus, you hang lamps and fans, the more you pay.
PPFD for veg: New LED grow lights Generation
HID lighting has finally been outmatched by the latest LED technology, making it possible for them to be replaced. In a way, this is reminiscent of the early 1900s, when flat screens were first introduced. The advantages of this technology were well-known, but the high prices of the leading producers kept them out of reach.
As for 350-400W, full spectrum LED systems and models can already do this. Running cool and lasting for years makes the greatest systems quite affordable. There is a wide range of ideal LED hanging distances. Using this information, you will be able to determine the proper wattage and position for your cannabis grow lights.