Frequently Asked Questions

LED grow lights are great because they are energy-efficient, durable, and have 'tuned' light spectrums to best meet the plant's needs. LED Grow Lights not only illuminates a room rather well and provides a nice warm glow but also is very environmentally friendly (no mercury). Fast and easy to install, convenient to control light spectra, increasing growth, and improving the yield appeal to more and more growers to change their HPS Lights.

Thousands of Successfully Shipped Orders and Thrilled Customers We have been in business since 2006 and are a highly-trusted led light manufacturer offering honest grow advice and top-of-the-line LED grow lights and other grow/harvest/extraction equipment. We have thousands of 5-STAR PRODUCT REVIEWS from satisfied customers." Seven Systems Make us Different! Click Here to Learn More.

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It is the cost differences for different countries except for the USA, which contain shipping costs, storage costs, and labor costs, etc not including the import tax.

For USA address, we'll ship out your goods within 48 hrs from the USA warehouse; For other countries' orders, pls kindly contact the salesman to confirm the correct lead time.

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Normally, your goods will be arranged within 24 hrs and they'll be at your door within 7 business days after shipment.

PAR
This is not a measurement at all, but instead, a type of light that can be absorbed by plants (and coincidentally seen by humans). It ranges from 400 to 700nm.

Lumens
This is a measure of the total apparent brightness of a light source and not how many photons are produced. As the cliche goes, “lumens are for humans.” You can think of it as the brightness of a single candle (although the real definition is more complex). By in large, lumens are not a useful measure of light intensity for plants since they overweight colors like green and underweight reds and blues. For instance, 1W of radiant flux at 550nm (green, which the human eye is very sensitive to) is 675 lumens. One watt of radiant flux at 660nm (deep red) is only 45 lumens. The red light will be more easily absorbed by your plant in photosynthesis than the green one, but your eye will see the green light as 15 times brighter than the red light!

Lux/Footcandle
This measures how much brightness is striking a unit of area. Contrast this with lumen which is the total amount of brightness coming from the light source in all directions. Lux = one lumen per meter squared. Footcandle = one lumen per foot squared.
Seedlings, clones, mother plants: 200-400 PPFD
Early to late Veg: 400-600 PPFD
Flowering: 600-900 PPFD
Some of you may be wondering about the LED grow lights that produce over 900 PPFD. Will a PPFD higher than 900 produce bigger buds on your plant? The answer to that is yes - only if you run a high CO2 in your grow environment. CO2 is measured by PPM and the CO2 level outside is 400-500 PPM. Plants grow just fine with that amount of CO2. Some advanced growers will add CO2 into their grow room to get the CO2 PPM in the range of 1,000-1,500. Running a higher CO2 PPM like that will allow your plant to absorb more PAR. On the flip side, if you are not supplementing with CO2 and provide your plant with too much PAR, then your plant could encounter problems.

"The critical difference is that PPFD measures the density of these photons falling on a particular surface.

PPF
PPF (Photosynthetic Photon Flux) measures the total amount of light produced by a grow light in terms of micromoles of photons produced per second (often written as umol/s or μmol/s). This is an important number because unlike PPFD (which will be explained below) it can’t be manipulated and tells you the full amount of light coming from the LED grow light.

PPFD
PPFD (Photosynthetic Photon Flux Density) measures the number of micromoles of photons striking a square meter per second (often written as μmol/m2/s, μmol/m2/s, or μmolm-2s-1).

Full daylight sun at noon in the summer is around 2000 μmol/m2/s. What your plants actually need, however, is likely to be much less than that. In fact, because the Sun’s intensity is only that bright for a small portion of the day and because the angle of that intensity changes throughout the day, providing that much light for an extended period of time would very likely be damaging to your plant. A ‘light response curve’ shows how effectively a plant utilizes light at differing intensities. Depending on the plant, at levels greater than 800-1000 μmol/m2/s the efficiency that a plant uses the light starts to slow. Meaning, you can provide your plant more light than this, but you might not see a huge change in outcome.
It’s worth noting that some LED companies can increase their PPFD numbers by measuring extremely close to the grow light or using spot-light like reflectors or lenses. An LED company should always report what distance their PPFD numbers were taken at (e.g., 24 in, etc.)."

"In comparison to HPS lights, LED Grow lights have a much longer lifespan. With time, HPS bulbs may become dimmer and lose efficiency. Even the actual operating cost over the lifetime of an HPS bulb increases with usage. However, LED bulbs offer a bit more power at the end of their lives.
As a grower, you are always looking for the best recipe for growth – ways to optimize results, minimize risks, and increase yield. You can realize this through predictable, high-quality, high production crops or plants delivered all year round. You aim to have maximum control over your investment and operational costs and want to find out how you can use LEDs to improve your business results. A successful LED-based growth strategy will result in a couple of promises.

Control heat and light separately



High levels of radiant heat can stress or even burn the plants. With LED lighting you can control heat and light separately. You can apply higher levels of light to plants with 67% less radiant heat than HPS lighting. A lower crop temperature means you will have to raise the ambient temperature in your greenhouse and manage the related change in humidity.

More light, less radiant heat
One important aspect is understanding how to grow your crops with LED lighting. When comparing the energy balance of LED lighting versus HPS lighting, the conversion of electricity into light and heat is different. Using the same amount of energy, LED modules deliver more light and less radiant heat. This does call for new growth strategies for high-wire crops.
In conclusion, it's wiser to choose led grow lights. "

This depends on the type of plant, the size of the plant, and how many plants you are trying to grow. A single light might be appropriate for a small pot with a single plant or a small seedling tray. As plants get larger or the required coverage area expands, more lights may be needed. Generally, if plants are growing well and have a compact, robust structure, they are getting enough light. If plants are weak, with elongated stems and many small leaves, this may indicate additional light needs to be provided. please learn more details from our led grow lights specification.

Different types of plants need different amounts of light. While seedlings or vegetative plants can require as much as 18 hours of light exposure each day, flowering plants benefit from at least 12 hours. please ask at the nursery for specific suggestions.

Yes, World Growing led grow lights are full-spectrum, moreover, the light height and brightness are adjustable during their growth cycles.

In general, most should be positioned 6 inches above the plants, you need to adjust the light height and brightness to get different PPFD outputs to match the plants growing at different periods.

PPFD (photosynthetic photon flux density) is the amount of PAR that falls on a given surface each second. PPFD is a spot measurement of a specific location on your plant canopy and it’s measured in micromoles per square meter per second (µmol/m2/s).

Seedlings, clones, mother plants: 200-400 PPFD

Early to late Veg: 400-800 PPFD

Flowering: 800-1200 PPFD

please check the correct PPFD FOOTPRINT MAPS from our led grow lights specification.