The Best Grow Lights for a 3×3 Grow Tent – Pictures, Specs, and More

What are the best grow light options for a 3×3 grow tent? Consider one of the following options: A Viparspectra P1500 (budget), A Mars Hydro TSW 2000 (performance), a Spider Farmer SE-3000 (Fancy), or a 250 watt HPS grow light (HPS option).

The most important factors to consider when choosing a grow light for a 3×3 foot grow space are the light intensity and uniform coverage area of the lights.

If you pick the wrong grow light your plants won’t grow to their full potential. All the options I mention below meet or exceed those requirements.

When you’re done reading this, don’t forget to check out my article on choosing the right size fan for your grow tent.

Budget Choice: Viparspectra P1500

Viparspectra P1500

   (Click Here to View or Buy at LED Grow Lights Depot)

Free Grow Guide to Download

The Viparspectra P1500 is the most modern design LED grow light from Viparspectra, a grow light manufacturer that has been around long enough to sell several generations of best selling LED Grow lights.

I bought the smaller P1000 model and wrote about it here.

This P1500 model will veg and flower your 3×3 foot grow tent. Is it the best performing or most powerful? No, but at ~$160 it offers a solid bang for your buck if you’re on a tight budget.

Why Choose Viparspectra P1500 for your 3×3 Grow Space:

I speak with growers who swear by their Viparspectra grow lights. As a matter of fact, they won’t switch to another brand despite there being options that offer higher performance.

These Viparspectra owners also swear by the reliability. The enthusiasm around Viparspectra is a great thing to see for a brand.

The dimming knob is very convenient. The fact that this Viparspectra P1500 isn’t overly powerful allows you to hang it close to your plants, saving you overhead space.

The light intensity is strong enough to cover a 3×3 foot grow space, preferably a grow tent for increased light reflection.

Viparspectra P1500:
Watts Consumed:150 watts
Peak Intensity:1000 micromoles (enough for seed to flower)
Coverage Area:Flowers 3x3ft
Spectrum: 640-660nm (far red), 3000-3500K (white), 6500-7500K (white)
Warranty:3 years
Where To Buy:Click Here
Video of my Viparspectra Grow Light:
Viparspectra P1000 Pro Series Grow Light | Test & Overview

Performance: Mars Hydro TSW-2000

mars hydro TSW 2000

(Click Here to View or Buy at LED Grow Lights Depot )

The Mars Hydro TSW-2000 is a modern quantum board style LED grow light. This grow light is rated for 3×3 feet of flowering coverage, slightly larger for vegetative growth.

Free Grow Guide to Download

I bought a different size Mars Hydro model for my 2×4 grow tent at home and it looks and performs great. This is one of the best selling LED grow light brands around.

Why Choose Mars Hydro TSW-2000 for a 3×3 foot Grow Space:

This TSW-2000 is a bit more powerful than the Viparspectra P1500 listed above. For that added performance, plus a few other features, you’ll pay a bit more.

With that said, if you have the money it’s totally worth it. The stronger light will result in better yields in your 3×3 foot grow space. You can remove the drivers on the TSW-2000 and hang them outside the grow tent with the extra cord length. This helps you keep your growing temperature down.

The spectrum coming from the TSW-2000 is similar to the Viparspectra (white + red) except the Mars Hydro also contains infrared, which helps plants resist any potential disease, and grow more dense buds.

Mars Hydro TSW-2000:
Watts Consumed:310 watts
Peak Intensity:1150 micromoles
Coverage Area:Flowers 3×3 feet
Spectrum:3000K (white), 5000K (white), 660nm (red) 760nm (infrared)
Voltage:120v / 240v
Warranty:3 year
Where to Buy:Click Here

Take a look at the buds people have grown with Mars Hydro grow lights:

mars hydro cannabis

Video of My Mars Hydro Grow Light:

Mars Hydro TSL-2000 Grow Light | Test and Overview

Click Here to See Prices and Reviews of The Mars Hydro TSW-2000 at LED Grow Lights Depot


Fancy Choice: Spider Farmer SE-3000

(Click Here to View on Amazon)

The fancy, high performance grow light option for a 3×3 foot space comes from another reputable LED grow light manufacturer, Spider Farmer.

This grow light differs from the previous two 3×3 foot grow light options. It differs because the design is newer and more efficient, the spectrum is the best, and it’s also the most expensive (but not by much). Below you’ll read why you get what you pay for with the SE-3000.

Why Choose the Spider Farmer SE-3000 grow light for 3×3 foot space?

I haven’t owned this model, but I’ve owned previous models from Spider Farmer and I know their product quality. I’ve also regularly encountered growers in the community who prefer Spider Farmer over other budget grow light brands.

There are three reasons why you get what you pay for when you pay a higher price to hang the Optic 4 Gen 4 grow light in your 3×3 foot grow space.

The first reason is the bar style design. The SE-3000 features the newest bar style grow light design, which is thought to be even more efficient at dissipating heat than the previous flat quantum board style design.

Don’t get me wrong, the flat quantum boards work just fine, and they will probably offer even more price value now since they’ve aged a bit and have to compete with the newer bar design grow lights.

The second reason is the Ultraviolet and Infrared spectrum. I’ve noticed that Ultraviolet spectrum being included on grow lights is pretty much going extinct.

The reason is unknown because ultraviolet rays are documented to increase THC levels. My guess is grow light manufacturers want to save money (what else is new?).

Infrared spectrum is also documented to help plants grow thicker stems and more dense buds, and it’s included on the Optic 4 Gen 4.

The third reason is the very strong light and the ability to hang this grow light at lower heights than the older quantum board designs which hang around 18 inches on average. You can hang this grow light pretty low, around 8 to 10 inches above the canopy, which will save you space when your cannabis plants are tall and you need the extra overhead space in your tent.

When you put a SE-3000 grow light in your 3×3 tent you’ll be getting all of these benefits.

SE-3000 Specifications:

Watts Consumed300 watts
Peak Intensity:1200+ micromoles
Coverage Area:3×3 ft flower area
Spectrum:660nm (red), 4800K-5000K (Cool white), 2800K-3000K (Warm white), UV, IR
Voltage:120v / 240v
Warranty:5 years!
Where to Buy:Click Here

If you don’t mind paying extra for a top-shelf product, the Spider Farmer SE-3000 is absolutely your match. Especially if you’re growing in a 3×3 foot area.

HPS Option: HPS Grow Light

(Click Here to View or Buy on Amazon)

If you have a 3×3 foot grow tent, and don’t mind using a non-LED grow light, you may want to consider this dimmable 400 watt HPS grow light. This grow light is priced nearly the same as the budget Viparspectra option above, but will provide you stronger light. It’s an older technology than LED but the advantage is the similar price point with stronger light that’ll be better for large yielding cannabis plants.

You won’t need all 400 watts in a 3×3 foot space, luckily this grow light is dimmable so you can dim it down to the 250 to 300 watt range.

Should you worry about heat when you put a HPS grow light in your 3×3 foot grow space? At 250 watts I wouldn’t worry too much. You really only have to be careful when you get to 400 watts and above.

Why Choose a HPS Grow Light for a 3×3 Foot Grow Tent?

  • Flowers a 3×3 foot space.
  • Offers the performance of a more expensive LED grow light at a budget price.
  • Low power consumption if you dim below 400 watts.

Click Here to View or Buy the iPower 250w HPS Grow Light on Amazon

iPower HPS Grow Light
Watts Consumed:400 watts
Coverage Area:3×3 feet
Spectrum:Red & Blue spectrum bulbs sold separately
Where To Buy:Click Here

Which of these grow lights would I personally choose for a 3×3 foot grow tent?

Growers often ask my opinion after reading my lists. My personal choice for a 3×3 foot grow tent would be either the Mars Hydro TSW-2000 or the Optic 4 Gen 4.

Both are very good lights and I think you’ll be very satisfied with either one. The Viparspectra could be a little stronger, and I’d personally rather have an LED grow light than an HPS grow light.

I don’t recommend the 400w HPS, but occasionally I talk to people who are on a tight budget. If that’s your case you can go with one of those.

Is 3×3 feet the best grow tent size?

In my opinion, 3×3 feet is not the best grow tent size. You can fit one to two plants, but with the recommended spacing of 2×2 feet per plant, fitting even two plants plus a humidifier can get cramped quickly.

I prefer 2×4 foot grow tents, or 4×4 foot grow tents. I’ve outlined the best grow light options for 2×4 foot grow tents here, and for 4×4 foot grow tents here.


How many watts do I need to grow cannabis in a 3×3 foot grow tent?

The smallest number of watts needed to grow cannabis in a 3×3 foot grow tent is 40 watts per plant, although the best grow lights use at least 200 watts for the whole tent.

How many cannabis plants fit in a 3×3 grow tent?

Two cannabis plants will fit in a 3×3 grow tent. It can vary depending how large the plants are allowed to grow.

What size inline fan should I use in a 3×3 grow tent?

An inline fan rated for 150 to 175 cfm will be sufficient for a 3×3 grow tent.

How do I control temperatures in a 3×3 grow tent?

If your grow tent is too hot, try cooling the room where the tent is located by opening a window or using an air conditioner. If the grow tent is too cold you may need to buy a space heater for the room the tent is located in.

How do I control humidity in a 3×3 grow tent?

You can control humidity in your grow tent by using a humidifier or dehumidifier.



My name is Nick, and I'm a home grower who spends time writing about indoor growing tools and setups. My goal is for 420ExpertGuide to be a one stop shop for indoor growers to find the information they need.