Viparspectra 300w Review, The True Story

LED grow lights are still pretty new. They are very effective when used within their limitations. As long as they are properly used, you will enjoy some delicious buds. In this Viparspectra 300w review, I will explain both the pros and cons of this grow light. You can decide if it jives with your grow plan.

Here are the 300W LED grow lights we’ll be reviewing:


I wish good LEDs were around before legalization came to my state. Back then, I kept a small four square foot perpetual harvest going. LEDs are perfect for that size grow. You could get a bunch of LED fixtures for large grows, but HID lighting would be both cheaper to run and better for the plants. The exception here are quantum boards and quantum boards. Look into them if you want, but I’m focusing on more affordable lighting now.

Today’s LED fixtures don’t generate much heat. Have you ever grown with an HID light in a grow tent? You could bake a potato in there! Heat from pumps, fans and dehumidifiers are another story… Investing in a good LED fixture will reduce the heat problem in a small enclosed grow area like a tent or covert cabinet.

Three potatoes wrapped in tin foil baking over flaming grill

The noise generated by an LED grow fixture is comparable to that of an HID ballast. In both cases, the noise comes from the cooling fan. You won’t notice it over the noise of a few aquarium pumps or an inline duct fan. Let’s make it simple. If you can answer yes to any of these questions, an 300w LED grow light may be a good choice for you:

  1. Do you have a small grow?
  2. Do you grow in a tent or small enclosed area?
  3. Even in larger areas, do you have problems controlling heat?
  4. Are you going to try perpetual growing?

Viparspectra Reflector Series 300-watt LED Grow Light

This light is a decent mid-priced and mid-quality LED fixture. It claims to replace a 250-watt HID light while drawing only 130 watts of power from the wall. An equally ambitious claim is that it delivers the perfect spectrum balance for optimal plant growth.This light is perfect for four square feet of canopy in the vegetative stage or three square feet of flowering canopy. Viparspectra rationalize this with an in-depth foray into par value, et al. Listen, don’t get caught up in par value. It’s not that important. You want 35 to 50 watts of actual electricity drawn from the wall for each square foot of canopy. Simple. Yet, as we’ll see here, this is a good light for smaller grows, hot grow areas and starting seedlings and clones. If you want dense, high quality buds, go with a high-end, high-draw LED. Or, use HPS.


  • Full spectrum
  • Quiet fan
  • Good heat dissipation
  • Can be lowered to about 18″ from the canopy


  • Weak light compared to high-end LED fixtures
  • Plastic construction – it’s strong, but it’s still plastic
  • For small grow areas only

Features And Benefits

Now let’s look at each important aspect of this specific light and see how it can benefit or hinder you.

Light Output

Lighting is critical for growing healthy plants and good bud. The 300w LED grow yield at harvest is directly related to the wattage per square foot available to the canopy during the flowering stage. Weak light in the 35 watt per square foot and less range produces small, loose popcorn buds. Intense light above around 45 watts per square foot yields hard, dense, tight and bristly buds. The yield maximizes as long as the plant has good genetics and you meet it’s other needs.

We’re talking about watts from the wall. That’s what you look for when deciding on either LED or HID lighting. The 300-watt in this light’s name is misleading. It doesn’t consume 300 watts, and it doesn’t replace any other 300-watt light. It draws about 130 watts. It’s a 130-watt light which is good for four square feet at the most. Lowering the light so its output focuses on three square feet of canopy would yield better buds. Keep in mind, three square feet is up to two plants if you are using the Sea of Green method.

Person swimming in an open, flat sea

Light Footprint

Congratulations to ViparSpectra for designing this fixture to have an efficient light footprint. When hung at the proper height from the canopy, most of the light falls in a rectangle measuring about two-by-three feet. This is opposed to other useless LED fixtures out there that simply spread their light out like an incandescent bulb.

This nice footprint makes the most out of every watt.

Heat Generation

This model generates about as much heat as any other LED grow light of comparable power draw. What sets it apart from lower quality lights is the way it deals with the heat it makes.

Cheaper models have a few vents on top of the unit to allow the heat from the LEDs and driver to escape. Your better fixtures, like this, incorporate a heat sink and fan. The best sink is made of aluminum. It sucks the heat away from the unit. The fan blows across the heat sink to keep everything cool.

This heat dissipation is important for the life of the unit. LEDs are notoriously susceptible to heat. They burn out, and you are left with a unit with dead diodes that cannot be replaced.

How you deal with the tiny amount of heat generated depends on your grow. If you are in an open space, like a basement, nothing is required. Even tents with adequate ventilation, say 150 cubic feet per minute, can deal with the heat. Stealth cabinets and tents that tend to run hot may present a bit of a problem with heat buildup. In this case, simply tie a duct into your exhaust line and secure the end near the top of the fixture. Of course, in any case, you may need that little extra heat. You can reverse your intake and exhaust so fresh air comes from the top and the stale air is moved out near the bottom. This will run the heat through your canopy.


Plants need light in several different wavelengths for the greatest growth. Cannabis prefers bluish light during veg and redder light during flower. Pot will grow when given almost any light, but there are some advantages to using a full-spectrum light like this one.

The ViparSpectra Reflector Series 300-watt LED grow light incorporates individual LEDs of specific wavelength outputs. Therefore, the light is customizable. All of the power is converted into light that the plant can actually use. No electricity is wasted.

A light bulb lying on short green grass

Let’s compare HPS and LED spectrums. HPS bulbs produce light across the entire spectrum, especially on the red end. Making light across the full spectrum, including the unneeded parts wastes electricity. Well-designed LED lights, like this, generate light only in the most desirable parts of the spectrum.

I was happy to see that there is no gimmicky veg/bloom switch on this model. If there was, this Viparspectra 300w review would have gone differently. These switches activate bluer LEDs when the switch is in the veg position and redder LEDs when bloom is selected. You need as much light intensity as possible.

Use For Seedlings And Clones

This fixture is fantastic for young plants. Seedlings and fresh clones need abundant light, but it can’t be too intense or hot. HID lights can fry a young cannabis plant. Even the high-end boards and COBs can be too much. This unit puts out the perfect amount of light for strong stem development and leaf formation. But it doesn’t put out so much light that you have to worry about leaf burn or bleaching. You can keep this light close, like you’re supposed to, and make use of all those 130 watts.

Online Reviews

Every grower has their own unique grow. Everyone has their own pet techniques and preferred equipment. So I love to look online and see what other growers think of the products I review. These following reviews are from actual growers who actually use this particular model.

Similar Fixtures

There is an array of LED grow lights out there, and they all want to be part of your grow. Let’s take a look at a few others and see how they stack up against the ViparSpectra 300w.

>>Check Price On Amazon<<

Viparspectra 300W Timer Series

This model is the same as the one reviewed here, but it has a built-in timer. This is useful because it will save you money on a separate timer.This model also has a veg/flower switch, but we’ll forgive Viparspectra for that, won’t we?

The timer is operated by a simple remote control. You simply set the amount of time you want the light on and the amount of time you want it dark. Then you start the cycle.

Let’s compare.

  • Similar light output
  • Similar heat generation
  • Same spectrum width
  • Handy built-in timer

Think about this model if you need a timer, but want to keep your grow area simple and uncluttered.

>> Check Price On Amazon<<

CDMall Full Spectrum 300w

This light compares to the ViparSpectra LED that I’ve reviewed here in almost every way. It draws the same amount of power and delivers full-spectrum light to the plants. Most online reviewers who have experience with LED fixtures comment on how quiet the fans are.The feature that makes this fixture stands out is the way it directs its light. Most fixtures in this price range use cheap reflectors. This utilizes focusing lenses, just like the expensive COB LED grow lights. These lenses focus light into the intended footprint instead of reflecting it away from the fixture in all directions.

Compared to the ViparSpectra:

  • Same quality construction
  • Also full spectrum
  • Better use of generated light, thanks to the lenses

Take a look at this light if you want the best efficiency.

>> Check Price On Amazon<<

Mars Hydro Full Spectrum 300w

Congratulations to Mars Hydro! They claim that their 300-watt light, which also draws 130 watts, is comparable to a 150-watt HID light. This is much more reasonable than the typical ‘130 watts equals 300 watts’ claim that is rampant in the industry nowadays.This light is very similar to the ViparSpectra 300w reflector light, but is made with cheaper material. I would not want to drop this fixture. The fans are also a bit louder.

How does it compare?

  • Same full spectrum light
  • Same power draw
  • Lower quality construction

Check out this light if a three-year warranty appeals to you.

>> Check Price On Amazon<<

In Conclusion…

The Viparspectra 300W is a good little light that is fine for a small one or two plant grow. It is also great for young plants. You have to keep its limitations in mind, though.

You won’t save much on electricity compared to HID lighting if you are giving your plants the amount of light they need. But you will save a ton of heat.

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