Best Carbon Filter for a Grow Tent

A carbon filter cleans the air your inline fan pulls out of a grow tent. Air passes through a bed of activated carbon, which adsorbs odors and airborne chemicals before the air leaves through the duct. For an indoor garden in a shared home, it is what keeps the smell of soil, nutrients and plants inside the tent.

This guide compares three 6-inch filters, the size that pairs with the 6-inch inline fans most tents use, from their published specifications. We did not test them ourselves, and we found no independent measurements of odor removal or airflow loss for these models.

Match the filter to the fan

Filter shopping starts with the fan. Our inline fan guide covers sizing in detail; the short version from LONGWELL’s published formulas:

1. Tent volume sets the base. One air exchange per minute: a 4x4x6.5 ft tent holds about 104 cubic feet, so the base is about 105 CFM.
2. The filter adds resistance. LONGWELL adds 25% to the required CFM for a carbon filter, 5% per 5 ft of flexible duct and 10% per 90-degree bend.
3. The filter’s rating should meet or beat the fan’s. LONGWELL says the filter’s CFM rating should be equal to or above the fan’s CFM rating.
4. Duct sizes should match. A 6-inch fan takes a 6-inch filter flange. Reducers add restriction.

AC Infinity lists its CLOUDLINE T6 6-inch fan at 402 to 425 CFM depending on the listing. The AC-DCF6’s 410 CFM rating falls in that range, and the other two filters are rated above it.

What to compare

• Rated airflow (CFM). The maker’s maximum. A higher rating than your fan means less restriction at the speeds you will actually run.
• Carbon type and grade. All three use Australian carbon. AC Infinity and Vivosun quote an IAV (iodine adsorption value) grade of 1200+; Can-Filters does not publish one.
• Bed depth. A thicker bed holds more carbon. AC Infinity lists 38 mm; Can-Filters lists 2 inches.
• Size and weight. A longer, heavier filter needs more headroom and a stronger hanging point.
• Pre-filter. A cloth sleeve that catches dust before it reaches the carbon. All three include one.

Specs side by side

	AC Infinity AC-DCF6	Vivosun 6-Inch	Can-Lite 6” 600 CFM
Duct opening	6”	6”	6” (built-in flange)
Rated airflow	410 CFM	455 CFM	600 CFM recommended max
Carbon	Australian Virgin RC412, 1200+ IAV	Australian virgin RC412, 1200+ IAV (spec table)*	100% Australian granular carbon
Bed depth	38 mm	Not stated	2”
Size	15.74 x 8.93 in.	15.7 x 8.9 x 8.9 in.	10” diameter x 24” tall
Weight	Not stated	Not stated	20 lb (14.2 lb carbon)
Pre-filter	Two washable cloths	Velcro pre-filter	Yes
Warranty	2 years (AC Infinity program)	Sold as-is, no warranty	Not stated

Figures are from each brand’s own product page, checked November 14, 2026. *Vivosun’s spec table says 1200+ IAV, but the feature list on the same page says “1050+ RC 412”.

AC Infinity Duct Carbon Filter 6” (AC-DCF6)

AC Infinity lists a 6-inch duct opening, 410 CFM maximum airflow, Australian Virgin RC412 carbon rated at 1200+ IAV in a 38 mm bed, a rust-resistant galvanized steel mesh with a gunmetal finish, and reversible aluminum flanges. The box includes two machine-washable pre-filter cloths, two hanging straps and two rope clips. AC Infinity says the filter can be used for intake or exhaust, and that reversing the flanges helps prolong its life.

It is the natural partner for an AC Infinity CLOUDLINE fan. Its 410 CFM rating is close to the CLOUDLINE T6’s 402 to 425 CFM, and SimpleHydroponic’s roundup of owner reports says owners commonly run the T6 below half speed in a 4x4, which keeps actual airflow well under the filter’s rating. AC Infinity’s warranty program covers its products for 2 years.

Vivosun 6-Inch Air Carbon Filter

Vivosun’s technical specs list a 455 CFM maximum airflow, a 6-inch duct size, RC412 Australian virgin charcoal at 1200+ IAV and a galvanized alloy steel body measuring 15.7 x 8.9 x 8.9 in. The package includes the filter, a changeable Velcro pre-filter and hanging belts. Note that the same page’s feature list describes the carbon as “1050+ RC 412”, so the grade is not stated consistently.

The trade-off is support: Vivosun’s product page says the filter is sold as-is with no warranty. It pairs naturally with Vivosun’s own 6-inch fans; see Vivosun vs AC Infinity for how the two ecosystems compare.

Can-Lite 6” 600 CFM

Can-Filters builds the Can-Lite for small to mid-size spaces. For the 6-inch, 600 CFM size it lists a 2-inch bed of 100% Australian granular carbon, 51% open perforation, a built-in 6-inch flange, a pre-filter, a 10-inch outside diameter and a 24-inch height, a total weight of 20 lb including 14.2 lb of carbon, and a maximum operating temperature of 80 °C. It is assembled in Vancouver, Washington.

It is the largest and heaviest filter here. A 600 CFM rating leaves plenty of headroom over a 6-inch fan, but at 24 inches tall it takes up more of the tent’s height, so check clearance above your light before you buy.

Installing a carbon filter

• Hang it high. LONGWELL recommends mounting the filter at the top of the tent and pulling air through it into the fan.
• Support the weight. Use the included straps on the top bars, and check your tent’s rated load; our grow tent guide lists them.
• Keep the duct short. Each bend costs about 10% of airflow, per LONGWELL.
• Leave a passive intake. At least 1 square foot per 400 CFM of exhaust, low on the opposite side, keeps the tent under slight negative pressure.
• Plan the replacement. LONGWELL puts carbon life at 12 to 18 months, less in humid conditions.

Inside the tent, a clip fan keeps air moving around the plants. The inline fan and filter only exchange it. Our grow tent setup guide shows where each piece goes.

How these picks were made

We picked widely sold 6-inch filters whose makers publish an airflow rating, compared them on rated CFM, carbon specification, size and warranty, and used LONGWELL’s published formulas for sizing. We did not test these filters ourselves; see how we research.