Ventilation|Updated 2025-01-01

Best Carbon Filters for Grow Tents in 2025

Eliminate cannabis odor completely with the right carbon filter

Jump to:#1 AC#2 Phresh#3 VIVOSUN

A quality carbon filter is essential for discreet growing. We tested the top options to find filters that actually eliminate odor without restricting airflow.

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#1Editor's Choice

AC Infinity Charcoal Carbon Filter 4"

Best Overall Performance

$34.99
(4.7)
AC Infinity Charcoal Carbon Filter 4"

Our Verdict

Australian RC-48 charcoal provides superior odor absorption. Pairs perfectly with AC Infinity fans for a complete system.

Best For: 2x2 to 3x3 tents with 4" ventilation
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Pros

  • +Premium Australian charcoal
  • +Excellent airflow
  • +1.5" thick carbon bed
  • +Machine-washable pre-filter
  • +2-year lifespan

Cons

  • -AC Infinity brand premium
  • -Slightly heavier
  • -Need matching flange size

Key Specifications

Size4" x 13"
CFM Rating200 CFM
Carbon TypeRC-48 Australian
Bed Depth1.5 inches
Weight6 lbs
#2Premium Pick

Phresh Filter 4"x12"

Best Premium Option

$89.99
(4.8)
Phresh Filter 4"x12"

Our Verdict

The filter commercial growers swear by. Costs more but lasts longer and handles higher CFM without odor breakthrough.

Best For: Growers who need absolute odor control
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Pros

  • +Industry-leading carbon quality
  • +Handles high CFM
  • +Zero odor breakthrough
  • +2+ year lifespan
  • +Commercial-grade construction

Cons

  • -Expensive
  • -Heavier than budget options
  • -Overkill for small grows

Key Specifications

Size4" x 12"
CFM Rating200 CFM
Carbon TypeRC-412 Premium
Bed Depth2 inches
Weight8 lbs
#3Budget Pick

VIVOSUN 4" Carbon Filter

Best Budget Option

$29.99
(4.5)
VIVOSUN 4" Carbon Filter

Our Verdict

Gets the job done at a great price. Perfect for beginners or smaller grows where budget matters.

Best For: Budget-conscious growers with small setups
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Pros

  • +Great price point
  • +Australian charcoal
  • +Reversible flange
  • +Includes pre-filter
  • +Works well for small tents

Cons

  • -Shorter lifespan (12-18 months)
  • -Thinner carbon bed
  • -May need replacement sooner

Key Specifications

Size4" x 14"
CFM Rating200 CFM
Carbon TypeAustralian Virgin
Bed Depth1.1 inches
Weight5 lbs

Carbon Filter Buying Guide

Matching Filter to Fan

Your filter and fan should have matching CFM ratings. If your fan is 200 CFM, get a 200+ CFM filter. Undersized filters cause odor breakthrough.

Size Matters

Match flange size to your ducting (4", 6", 8"). For most home grows, 4" is sufficient. 6" for larger 4x4+ tents. The filter body should fit inside your tent.

When to Replace

Most filters last 12-24 months depending on quality and use. If you start smelling odor outside the tent, it's time to replace. Running at lower CFM extends life.

Frequently Asked Questions

Should the filter go inside or outside the tent?
Inside is best. Mount it high in the tent (hot, smelly air rises), connect to your inline fan, and exhaust outside the tent. This pulls air through the filter.
Can I wash or recharge carbon filters?
No. Unlike some industrial filters, grow room carbon filters cannot be recharged. Once the carbon is saturated, replace the filter. You can wash the pre-filter sleeve though.
Do I need a carbon filter for just 1-2 plants?
Yes, if discretion matters. Even one plant in flower produces significant odor. A carbon filter is cheap insurance for stealth growing.

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