How many watts do I need for a 2x4 grow tent?

THCFarmer's member data suggests 200–300 W of real LED draw for a 2x4, with a median of 280 W. 200 W is the low end, about 25 W per square foot.

Why do some lights leave the ends of a 2x4 dim?

A square light board centered in a long tent puts most of its light in the middle. Coco For Cannabis's map of a 200 W SF2000 found areas under 500 µmol/m²/s at both ends of a 2x4. Long fixtures, bar lights or two small lights side by side spread light more evenly.

What size inline fan does a 2x4 tent need?

A 2x4x6 ft tent holds 48 cubic feet. With a carbon filter and a short duct run, LONGWELL's formulas give well under 190 CFM, the top of the 4-inch range. A 6-inch fan also works and will run quietly at low speed.

How many plants fit in a 2x4 tent?

Mars Hydro lists its 2x4 kit tent for 2–4 plants, and AC Infinity's 2x4 kit ships with four 5-gallon fabric pots. Gorilla's size guide gives 2–8 depending on training.

Best 2x4 Grow Tent Kit: 3 Brands Compared

By GrowRighteous Editorial Team (AI-assisted research) · Updated November 13, 2026 (first published November 13, 2026)

Best for	Product	Why	Link
Most light for a full 2x4	Mars Hydro TSL2000 2x4 kit	300 W light in the 200–300 W range growers use for a 2x4. An earlier version measured an even 727 µmol/m²/s across a 2x4.	Check price
Efficient light, smaller canopy	Spider Farmer 2x4 kit with SF2000	Independently measured as efficient, but best sized for about a 2x3 flowering area.	Check price
Most automation	AC Infinity AI+ 2x4 kit (CLOUDLAB 642)	AI+ controller, a 6-inch fan, a clip fan and a CLOUDLAB 642 tent. Light output not published.	Check price

A 2x4 tent is the most common first tent after a closet grow: big enough for a few plants, small enough for a spare-room corner. The long, narrow shape is also what trips up most kits. A light that is bright in the middle can leave both ends of the tent noticeably dimmer.

The kits side by side

From each brand’s listing, checked November 13, 2026.

	Mars Hydro TSL2000 kit	Spider Farmer SF2000 kit	AC Infinity AI+ 2x4 kit
Light	TSL2000, 300 W, PPF 717 µmol/s, 2.6 µmol/J	SF2000, 200 W, PPF 608.5 µmol/s (see note), 2.7 µmol/J	IONBOARD S24 (output not published)
Independent PAR data	Earlier version: 727.2 avg over 2x4	Earlier version: 572.6 avg over 2x4	None found
Tent	4×2×6 ft, 1680D, 110 lb support	2×4×6 ft	CLOUDLAB 642, 24×48×72 in
Exhaust	4-inch, 205 CFM, speed controller	4-inch inline fan, GGS controller kit	CLOUDLINE 6 (6-inch), CONTROLLER AI+
Carbon filter	4-inch	4-inch	6-inch
Clip fan	Yes (315 CFM listed)	No	CLOUDRAY S6
Other	Ducting, 3 clamps, 4 grow bags, trellis, scissors, hygrometer, 2 vent covers, 2 corner brackets	5 grow bags	8 ft duct, clamps, tape, ties, 4 × 5-gal pots, trellis, shears
Light warranty	5 years	5 years (full in year 1)	2 years

Light: the deciding factor

THCFarmer’s member data puts the usual draw for flowering a full 2x4 at 200–300 W, with a median of 280 W, and warns that “a single square board leaves both ends weak.”

Mars Hydro TSL2000 (300 W). Coco For Cannabis tested an earlier TSL 2000 on June 8, 2020 in a 2x4 area at 14.5 inches: 286 W draw, 727.2 µmol/m²/s average with a low of 524, and 523.6 µmol/s of usable PPF. The reviewer rated its distribution highly, attributing it to a fixture “only slightly smaller than the space it is designed to cover.” That unit used Epistar diodes; the current kit’s light is listed with Bridgelux diodes, 717 µmol/s and 2.6 µmol/J, and has not been independently tested that we could find. The measured efficiency of the older unit was lower (1.83 µmol/J usable) than the SF2000’s.

Spider Farmer SF2000 (200 W). The same tester measured a 2020 SF2000 at 201 W, averaging 572.6 µmol/m²/s across a 2x4 with a low of 272, and recommended planning on a 2x3 flowering area for full coverage. It was more efficient (2.05 µmol/J usable) but simply puts out less light. Spider Farmer’s own spec sheet for the 2026 version lists a PPF and efficacy that don’t reconcile at 200 W; details in our SF2000 review.

AC Infinity IONBOARD S24. The kit listing names the light but we could not find a published wattage-verified PPF or an independent PAR map for it, so we can’t compare its output.

Want to check a light against your own target? Use the grow light calculator.

Tent and ventilation

A 2x4x6 tent holds about 48 cubic feet. By LONGWELL’s formulas, even with a carbon filter and a few feet of duct, that is well inside a 4-inch fan’s range. The Mars Hydro and Spider Farmer kits use 4-inch fans and filters; AC Infinity uses a 6-inch fan and filter, which is more capacity than the tent needs but can run slowly and quietly. Run your own numbers with the fan CFM calculator.

Mars Hydro lists its 1680D kit tent with a 110 lb support capacity. AC Infinity sells the CLOUDLAB 642 as part of its “Thickest Poles and Canvas” range; we found published pole and load specs only for its 4x4 sibling, covered in our grow tent guide. Spider Farmer’s kit listing gives the tent size but not fabric or pole details.

Two small inconsistencies in Mars Hydro’s listing: the spec table says 10 m of duct while the feature text says 25 ft, and one Q&A answer gives the tent height as 5.9 ft against 6 ft in the title.

What’s missing

Spider Farmer: no clip fan. A 2x4 benefits from one to move air through the canopy.
All three: no dehumidifier or pH meter. See dehumidifiers and pH meters.
Availability: when we checked, AC Infinity listed the AI+ 2x4 kit as a pre-order shipping by December 29, 2026.

Which to buy

You want the whole 2x4 lit: the Mars Hydro TSL2000 kit has the most light, and the measurement of its predecessor shows even coverage across the full footprint.
You will grow fewer plants or use a 2x3 area: the Spider Farmer kit’s light is efficient and has a well-documented track record.
You want automation and will add your own light later if needed: the AC Infinity kit has the most capable controller and tent, but no published light output.

For bigger spaces, see the best 4x4 grow tent kits.

How these picks were made

We compared each kit’s listed contents, then weighted the light by independent PAR measurements where they exist and by THCFarmer’s member wattage data where they don’t. We did not test these kits ourselves; see how we research.