What is the Right LED Wattage for a 4×4 Grow Tent


A lot of our growers find that our 4×4 grow tent is a perfect size for their homes and their growth goals. But if you have just switched or are planning to move from a 4×2 or smaller size to a 4×4 tent, you probably are considering how to match the LED grow light wattage for a 4×4 grow tent.

In this post, we want to focus on LED grow lights. The price of LED lights is relatively high so if your budget for lights is less than $200, consider investing in HPS lights. Also, be aware, off-brand lamps can be dangerous and unreliable, and likely will not be a great long-term solution for your indoor growth.

Why should you choose LED grow lights?

Grow lights are a necessity for indoor growing, especially in a grow tent. When choosing a light, we want to simulate the perfect lighting conditions created by the Sun, since the spectrum produced by the Sun is exactly what plants use in their natural environments to photosynthesize. LED lights also use extremely low energy and generate very little heat. They can also provide a full spectrum of light that will take care of a plant through every stage of growth. Generally speaking, different colors on the light spectrum play different roles in plant growth.

Blue light promotes the growth of stems, branches, and leaves, while red light promotes the growth of buds and flowers. In addition, green and yellow light also play roles in helping plant growth, however, for most home growers, the focus is on blue and red. This is why when you search for LED grow lights online, the LEDs are shown as purple, a mixture of blue and red.

Tips for choosing an LED grow light for your 4×4 tent

How many watts per square foot for LED lights? -Right LED Wattage

According to our current data, the average wattage required per square foot is 32 watts (although this also depends on the plant, so we are taking averages here), so a 4×4 tent theoretically requires 512 watts for complete coverage. This number can float between 500 watts and 600 watts. In actual use, many LED manufacturers will use more energy-saving bulbs, so the LED light watts in use are often lower than this range. It’s important to make sure you’re buying from a trusted manufacturer.

What plants can you grow in a 4×4 tent?

Different plants require different light intensities. In general, plants that thrive on foliage require less light, these are usually plants that grow under tall trees because their leaves are large enough to catch extra light. such as Chinese evergreens, Ponytail palms, Dracaena, Philodendrons, and other aroids. Many vegetables also fall under this category as you probably won’t need them to flower. As a quick note, if you only want to grow some leafy greens, you can use low-light grow lights.
Flowering plants theoretically need more light to get the energy they need to bloom. Plants like marijuana, Cacti, and succulents all fall into this category.

The ideal plant growth spectrum-Right LED Wattage for a 4×4 Grow Tent

As we mentioned, different stages of plant growth require different colors of light. Excellent LED grow lights need to cover the whole cycle of plant growth and must provide the necessary light spectrum for those various stages of growth.

By combining different wavelengths, LED grow lights can provide either the full light spectrum or variations of the color spectrum so that you can emphasize certain wavelengths that match the specific period in the growing cycle. When you are looking for a new lamp, you’ll want to find an LED system that covers the entire light spectrum but if you prefer, one that also can be adjusted to specific growth periods. The goal, for the vegetative stage, for example, is to have a 4:1 ratio of blue-to-red light. Be sure to take the time to research your specific plants’ needs before you purchase your new light.

Light intensity


VIVOSUN VS2000 grows the light intensity

The way plants grow at various stages of growth is, on one hand, affected by the spectrum it receives, and on the other hand, by the intensity of the light, measured in lumens (or lux), but also the Photosynthetic Active Radiation (PAR value, measured as PPFD) plays a big role.

For this section, we’ll mainly discuss how to think about finding the right intensity. Too high or too weak of light intensity can have a potentially damaging effect on your plant’s growth. Each plant requires a specific lumens coverage for a given area. Cannabis, for example, requires between 300-800 lux.

Wrap-up Right LED Wattage

Plants have a variety of lighting needs throughout their growth cycle, including both the color of the light and the intensity of light. When you are choosing a new fixture for your 4×4 grow tent, you’ll want to consider wattage, the type of plants you’re growing, and factors like the light spectrum, lumens, output, along with cost, electricity usage, and how much heat the lamp will produce. Take these ideas as a starting point rather than a comprehensive list, growing is as much reading as it is planting, but the results are worth it!

If you are looking for powerful coverage and a complete light spectrum, the VS4000 grow light is our go-to. Although it is only 400 watts, the lamp produces 2.9μmol/J, far exceeding the energy output of other grow lights on the market. The VS4000 also comes with a dimming knob that makes it adaptable to different growing periods by adjusting its output from 40% to 100%.

If you are just starting to set up your 4×4 space, you may also want to consider buying grow tent kit, which offers all of the necessary equipment to start growing, including a tent, a light, ventilation, and a number of handy accessories.

If you have any questions, please don’t hesitate to reach out to us!

And be sure to check out our other blog posts for useful tips on becoming a great grower!

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  1. Quick and dirty for we all tryna find the answer: bout 512 watts.
    how many watts per square foot for LED lights tho ?

    • That’s right, it is indeed the same because the plants are receiving the same amount of energy from a single engery source. Actually, you’ll likely be able to produce more with a single plant.

  2. Thank you very much, Maybe you can help. I have a 380w Led but it bleaches my plants the tips closest to the light will turn white. Is this too strong or not a good light?

    • It sounds like your light may be too close to the plant tops. Maybe you can try to move the light further away and see if it helps fix the problem.

  3. Is it a discount to purchase a whole kit at once vs building it a little at a time with all the same components?

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