5 Best Dehumidifiers for Grow Tent [In 2025]

If you’re serious about indoor growing, you know that managing humidity is just as crucial as controlling light and temperature. Excess moisture in your grow tent can quickly lead to mold, mildew, and plant diseases that can devastate your carefully nurtured crops. That’s where a quality dehumidifier comes in – it’s not just an accessory, but an essential component for successful indoor gardening.

In this comprehensive guide, I’ll walk you through everything you need to know about selecting the perfect dehumidifier for your grow tent. From compact units for small setups to powerful models for commercial operations, we’ve researched and reviewed the top performers on the market today. Whether you’re growing herbs, vegetables, flowers, or other plants, finding the right humidity balance is critical to your success.

Let’s dive into the world of grow tent dehumidifiers and discover how the right choice can make all the difference for your indoor garden.

Top 5 Dehumidifiers for Grow Tents Reviewed

VIVOSUN Small Space Mini Dehumidifier

Product Specifications

• Capacity: 400ml per day (at 85% RH)
• Coverage Area: 215-269 sq. ft.
• Tank Size: 1.3L
• Dimensions: 5.1″D x 7.1″W x 11.2″H
• Weight: 4.4 pounds
• Special Features: Auto shut-off, LED power indicator, built-in handle
• Power Consumption: Energy-efficient design

Pros and Cons

Pros:

• Compact size makes it perfect for small grow tents
• Very energy efficient operation
• Ultra-quiet performance won’t disturb surrounding areas
• Built-in handle for easy repositioning
• Auto shut-off prevents overflow when tank is full
• Modern design blends well with growing equipment
• Affordable price point for beginners

Cons:

• Limited capacity only suitable for very small spaces
• No continuous drainage option
• Blue LED light may affect plant light cycles (some users paint over it)
• Not suitable for larger grow operations
• Manual tank emptying required

Best For

The VIVOSUN Mini Dehumidifier is ideal for first-time growers with small grow tents up to 3×3 feet. It’s perfect if you’re growing just a few plants and need basic humidity control without breaking the bank. This unit is also great for those concerned about energy costs or noise levels, as it operates extremely efficiently and quietly. However, if you’re running a larger operation or need set-and-forget capability, you’ll want to look at models with higher capacity and continuous drainage options.

Spider Farmer Dehumidifier with Drain Hose

Product Specifications

• Capacity: 32 pints per day (at 95°F, 90% RH)
• Coverage Area: Up to 2000 sq. ft.
• Tank Size: 2.1L
• Dimensions: 11.81″D x 7.87″W x 19.4″H
• Weight: 24.9 pounds
• Special Features: Air duct system, humidity sensor probe, 24-hour timer, digital display, continuous drain option
• Special Design: Can be placed outside tent with ducting to prevent adding heat

Pros and Cons

Pros:

• Unique air duct design keeps heat-generating components outside your grow tent
• External humidity sensor provides accurate readings directly from your plants’ environment
• Digital display makes monitoring and adjustments simple
• Continuous drainage option eliminates need for manual emptying
• Adjustable humidity setting from 30% to 80%
• Three operational modes for different situations
• 360° rotating wheels for easy positioning
• Washable filter reduces maintenance costs

Cons:

• Higher initial investment than basic models
• Relatively large footprint requires space consideration
• Some users report fan noise might be noticeable
• External sensor wire requires careful placement

Best For

The Spider Farmer Dehumidifier is the perfect match for serious growers with medium to large grow tents (3×3 to 4×4 feet). Its standout feature is the external placement with ducting, which prevents adding unwanted heat to your growing environment – a crucial advantage for temperature-sensitive plants. The remote sensor is a game-changer for precise humidity control directly in the plant zone. This model is ideal for growers who want professional-level results without constant maintenance, thanks to its continuous drainage and automated features.

COAIRO 104 Pint Whole House Dehumidifier

Product Specifications

• Capacity: 104 pints per day (at saturation)
• Coverage Area: Up to 3000 sq. ft.
• Dimensions: 22.64″D x 14.65″W x 19.88″H
• Special Features: Fresh air function, wired LCD controller, adjustable airflow (229CFM/309CFM), auto restart, auto defrost
• Installation Options: Side or top air outlet mounting
• Warranty: 5-year limited warranty

Pros and Cons

Pros:

• Exceptional moisture removal capacity for large or multiple grow tents
• Unique fresh air function brings outside air in – ideal for sealed grow environments
• Multiple ducting capability for servicing different areas simultaneously
• Professional-grade LCD controller provides comprehensive monitoring
• Two airflow levels for customized operation
• Automatic defrosting prevents coil freezing in cooler environments
• Durable construction with 5-year warranty coverage
• MERV-10 filter improves air quality

Cons:

• Significant investment cost not suitable for casual growers
• Large size requires substantial space for installation
• Higher power consumption than smaller units
• External pump required if gravity drainage isn’t possible
• Heavy unit (difficult for one person to move)

Best For

The COAIRO 104 Pint Dehumidifier is built for commercial-level growing operations or multiple large grow tents. If you’re managing a serious growing business or have converted an entire room or basement to growing, this powerhouse provides the industrial-strength dehumidification you need. The fresh air function is particularly valuable for sealed grow rooms where air exchange is limited. This unit is overkill for single small tents but delivers unmatched performance for large-scale operations where humidity control is mission-critical.

Stropum Automatic Small Dehumidifier

Product Specifications

• Capacity: 800ml per day (tested reducing 80% to 45% humidity in 50 mins in 9 cubic feet space)
• Dimensions: 2.35″D x 3.9″W x 5.9″H
• Tank Volume: 800ml
• Special Features: Temperature control switch, digital display, adjustable humidity control, AT/MT operation modes
• Installation Options: Hook or rail installation
• Voltage: Compatible with 110V-240V

Pros and Cons

Pros:

• Ultra-compact size fits in very tight spaces
• Temperature control function allows integrated climate management
• Continuous drainage via included tubing eliminates manual emptying
• Two operation modes for different needs (continuous or target humidity)
• Versatile installation options (hook or rail mounting)
• Works with wide voltage range (110V-240V)
• Extremely efficient in small enclosed spaces

Cons:

• Requires DIY wiring (power cord not included)
• Limited capacity only suitable for very small grow tents
• Primarily designed for electrical cabinets rather than grow tents
• Some technical knowledge required for installation
• Not as user-friendly as plug-and-play options

Best For

The Stropum Automatic Small Dehumidifier is perfect for micro-growers with very limited space or those needing targeted dehumidification in specific areas of their grow setup. Its tiny footprint makes it ideal for small grow boxes, cabinets, or drying areas where larger units simply won’t fit. The DIY aspect makes it less suitable for beginners, but experienced growers will appreciate its versatility and efficient performance in confined spaces. If you’re comfortable with basic wiring and need precision humidity control in a tiny area, this specialized unit delivers outstanding results.

COAIRO 90 Pint Whole House Dehumidifier

Product Specifications

• Capacity: 90 pints per day (at saturation)
• Coverage Area: Up to 2300 sq. ft.
• Dimensions: 22.64″D x 14.65″W x 19.88″H
• Weight: 89.07 pounds
• Special Features: Fresh air function, wired LCD controller, two airflow levels (229CFM/309CFM), auto restart, auto defrost
• Installation Options: Side or top air outlet mounting
• Warranty: 5-year limited warranty

Pros and Cons

Pros:

• Powerful dehumidification suitable for large grow operations
• Fresh air function provides ventilation without separate equipment
• Wired LCD controller can be placed in convenient monitoring location
• Multiple ducting options for flexible installation
• Automatic features (restart, defrost) provide worry-free operation
• Included MERV-10 filter improves air quality
• Durable construction backed by comprehensive warranty
• Professional-grade performance for serious growers

Cons:

• High initial investment cost
• Large size requires significant installation space
• External pump needed if gravity drainage isn’t available
• Heavier power consumption than residential models
• Substantial weight makes installation challenging

Best For

The COAIRO 90 Pint Dehumidifier is slightly scaled down from its 104-pint sibling but still delivers professional-grade performance for larger grow operations. This model is ideal for growers who need serious dehumidification for spaces up to 2300 square feet – perfect for commercial operations or dedicated grow rooms with multiple tents. The remote control panel is particularly valuable for monitoring conditions without entering the grow environment. While overkill for hobbyists, this unit provides the reliability and capacity needed by serious growers who can’t afford equipment failures or humidity spikes.

Understanding Humidity Control in Grow Tents

Why Humidity Control Matters for Plant Growth

Think of humidity as the invisible factor that can make or break your grow operation. Plants interact with moisture in the air constantly through a process called transpiration – essentially the plant version of sweating. When humidity levels are in the sweet spot, your plants can properly absorb nutrients, photosynthesize efficiently, and grow robust stems and foliage.

Too much humidity, however, creates a cascade of problems. Water can’t evaporate properly from leaves, transpiration slows down, and nutrient absorption becomes compromised. The result? Stunted growth, weak stems, and plants that never reach their full potential.

But it’s not just about plant health – it’s about the quality of your yield. Proper humidity management directly impacts the essential oil production in aromatic plants, the potency of medicinal varieties, and the overall harvest quality of any crop you’re growing.

The Risks of Excessive Moisture in Grow Tents

Left unchecked, high humidity in your grow tent becomes a breeding ground for trouble. The enclosed environment already creates ideal conditions for moisture buildup, and when combined with the warmth from grow lights, you’ve essentially created a perfect environment for unwanted visitors.

Mold and mildew can develop within 24-48 hours in high-humidity environments, often starting on the undersides of leaves where you might not immediately notice them. Once established, these fungi spread rapidly, potentially contaminating an entire crop. Powdery mildew, botrytis (gray mold), and other fungal pathogens thrive when relative humidity stays above 65% for extended periods.

Even more concerning is the risk of root rot, which occurs when excess moisture prevents proper oxygen uptake in the root zone. By the time you notice the symptoms – yellowing leaves and wilting despite wet soil – significant damage has already occurred.

Beyond plant diseases, high humidity creates ideal conditions for pests like fungus gnats, whose larvae feed on root hairs and bring additional diseases. Managing humidity is truly your first line of defense against these common grow room challenges.

Ideal Humidity Levels for Different Growing Stages

What makes humidity management tricky is that plants need different moisture levels at different stages of growth. Here’s a quick breakdown:

• Seedlings/clones: 70-75% relative humidity (RH) – Young plants haven’t developed extensive root systems yet, so they absorb much of their moisture through their leaves
• Vegetative stage: 50-70% RH – As plants develop stronger roots, they can tolerate slightly lower humidity levels
• Early flowering: 40-50% RH – Lower humidity helps prevent mold while allowing proper nutrient uptake
• Late flowering: 30-40% RH – Even lower humidity during this crucial stage prevents bud rot and maximizes resin production

The ability to precisely control humidity throughout these stages is what separates amateur grows from professional operations. A quality dehumidifier gives you that control, allowing you to dial in the perfect environment as your plants progress through their lifecycle.

Key Features to Look for in a Grow Tent Dehumidifier

Capacity and Coverage Area

When shopping for a dehumidifier, you’ll notice that manufacturers list their capacity in pints of moisture removed per day, typically measured at specific temperature and humidity conditions. This number is crucial – undersize your dehumidifier, and you’ll constantly battle high humidity; oversize it, and you’ll waste energy and potentially create too dry an environment.

For small grow tents (2×2 or 3×3), a compact unit that removes 10-20 pints daily is often sufficient. Medium tents (4×4 or 5×5) generally require 30-50 pint capacity. For larger operations or multiple tents, consider whole-room units capable of removing 70+ pints per day.

Coverage area, typically listed in square feet, is another important specification. However, remember that grow tents create more moisture than typical living spaces, so I recommend choosing a dehumidifier rated for at least 25-50% more square footage than your actual grow space.

Drainage Options

Nothing derails a carefully planned grow operation like returning from a weekend away to find your dehumidifier shut off because its tank filled up. That’s why drainage options should be a top priority in your selection process.

The most basic units feature a collection tank that needs manual emptying – fine if you’re always around and have a small operation. But for serious growers, continuous drainage capability is essential. Look for units with built-in pumps that can push water to a drain or units that can be connected to a standard garden hose for gravity drainage.

Some advanced models even integrate with your existing irrigation systems, allowing you to recycle the collected water back to your plants – an eco-friendly approach that can save resources over time.

Energy Efficiency

Grow operations already consume significant electricity through lighting, ventilation, and other equipment. Adding an energy-hungry dehumidifier can substantially increase your utility bills if you’re not careful.

Look for Energy Star-rated models where available, as they typically use 30% less energy than non-certified units. Some dehumidifiers feature eco modes that automatically adjust operation based on current conditions, running only when needed rather than continuously.

Pay attention to the amperage draw as well, especially if you’re running multiple pieces of equipment on the same circuit. The last thing you want is to trip breakers during critical plant growth phases.

Noise Levels

While plants don’t mind noise, you might – especially if your grow tent is located in or near living spaces. Dehumidifier noise levels typically range from whisper-quiet 35 decibels (comparable to a library) to a more noticeable 60+ decibels (similar to normal conversation).

Compressor-based units are generally louder than thermoelectric models but offer greater capacity. If noise is a concern, look for units with multiple fan speeds so you can reduce noise when you’re nearby and maximize performance when you’re not.

Some manufacturers specifically design their units for quiet operation, using sound-dampening technology and special fan designs to minimize operational noise while maintaining efficiency.

Smart Controls and Monitoring

Today’s best dehumidifiers offer sophisticated control options that take the guesswork out of humidity management. Basic models feature simple humidistats that turn the unit on and off to maintain your target humidity level. More advanced options include:

• Digital displays showing current humidity levels
• Programmable timers to coordinate with light cycles
• Remote sensors that can be placed in different areas of your grow space
• WiFi connectivity for monitoring from your smartphone
• Integration with other smart grow equipment

The ability to precisely monitor and adjust humidity from anywhere provides peace of mind and ensures optimal growing conditions around the clock. For serious growers, these features justify the higher price tag by delivering better results and reducing the risk of crop loss.

Sizing Your Dehumidifier for Your Grow Tent

Calculating Your Dehumidification Needs

Getting the right size dehumidifier is crucial – too small and you’ll fight a losing battle against moisture; too large and you’ll waste energy and potentially create too dry an environment. Here’s a practical approach to calculating your needs:

First, determine your grow tent’s volume in cubic feet (length × width × height). For example, a 4×4×6.5 foot tent has a volume of 104 cubic feet.

Next, consider your growing style:

• Soil growing typically produces less moisture than hydroponic or aeroponic systems
• The number of plants matters – more plants means more transpiration
• Growth stage impacts moisture production – flowering plants typically release less moisture than those in vegetative growth

As a general rule:

• Small tents (2×2 to 3×3): 10-30 pint capacity
• Medium tents (4×4 to 5×5): 30-50 pint capacity
• Large tents or multiple tents: 50+ pint capacity

Remember that manufacturers often list “pints per day” under ideal conditions – typically 80°F and 60% relative humidity. In real-world grow environments, especially with higher temperatures, actual performance may be lower. It’s always better to have slightly more capacity than you think you need.

Matching Dehumidifier Capacity to Tent Size

Beyond pure capacity, other factors should influence your dehumidifier selection based on tent size:

For small tents, compact units like the VIVOSUN or Stropum models make sense not just for their appropriate capacity but also because they won’t take up valuable floor space. In tight growing environments, every inch counts!

For medium tents, the Spider Farmer’s external placement design becomes particularly valuable. By keeping the heat-generating components outside the tent, you can maintain more precise temperature control while still delivering the humidity management you need.

For large tents or multiple-tent setups, whole-room units like the COAIRO models provide the industrial-strength performance required. Their ducting capabilities allow you to service multiple growing areas from a single unit, potentially saving money compared to purchasing several smaller units.

Consider future expansion as well – if you’re planning to add more growing space, investing in a slightly larger dehumidifier now might save you from needing to upgrade later.

Installation Tips for Maximum Efficiency

Optimal Placement Within or Outside the Tent

Where you position your dehumidifier can significantly impact its effectiveness. Here are some placement guidelines for maximum performance:

Inside the tent:

• Position the unit away from direct light to prevent plastic degradation
• Elevate it slightly off the floor to improve air circulation
• Keep at least 8-12 inches of clearance around air intake and exhaust
• Place it on the opposite side from fans to create circular airflow
• Avoid positioning directly above plants to prevent condensation drips

Outside the tent (for units with ducting):

• Position intake duct near the top of the tent where humid air collects
• Return dried air near the bottom for complete air circulation
• Keep duct runs as short and straight as possible
• Use insulated ducting if moving through significantly different temperature zones
• Secure all connections to prevent air leaks

Remember that dehumidifiers generate heat during operation. For smaller tents where temperature management is already challenging, external placement with ducting (like the Spider Farmer model) can prevent unwanted heat buildup inside your growing environment.

Setting Up Continuous Drainage

The convenience of continuous drainage cannot be overstated for serious growers. Here’s how to set it up effectively:

For gravity drainage:

1. Position the dehumidifier higher than your drainage point
2. Connect the included drain hose or a standard garden hose to the drain port
3. Secure the connection with hose clamps if needed
4. Run the hose to a floor drain, utility sink, or collection container
5. Ensure the hose has a continuous downward slope to prevent water backup

For pump drainage (required if draining upward):

1. Connect the pump according to manufacturer instructions
2. Position the discharge hose securely to prevent leaks
3. Consider a backup collection container in case of pump failure
4. Test the system thoroughly before leaving it unattended

Some growers integrate dehumidifier drainage with their irrigation systems, collecting and reusing the water after proper treatment. This eco-friendly approach can be particularly valuable in areas with water restrictions or high utility costs.

Maintenance Requirements

Even the best dehumidifier will fail prematurely without proper maintenance. Establish a regular maintenance schedule:

Weekly tasks:

• Check and clean air filters
• Inspect drain hoses for clogs or kinks
• Verify humidity readings with a separate hygrometer
• Clean any dust from air intakes and exhausts

Monthly tasks:

• Deep clean the water tank with mild soap to prevent algae growth
• Check and tighten any loose ducting connections
• Inspect coils for dust buildup (clean with soft brush if needed)
• Test automatic functions like auto-shutoff

Seasonal tasks:

• Complete coil cleaning with appropriate cleaner
• Check and clean internal components per manufacturer instructions
• Inspect electrical connections for signs of wear
• Recalibrate humidity sensors if possible

Most dehumidifier failures result from improper maintenance. Following these steps will significantly extend the life of your unit and ensure consistent performance when your plants need it most.

Integrating Dehumidifiers with Other Growing Equipment

Coordinating with Ventilation Systems

Your dehumidifier doesn’t work in isolation – it’s part of a comprehensive climate control system that includes fans, carbon filters, and possibly air conditioning. Proper coordination between these components is essential for optimal results.

Intake and exhaust fans create air exchange that naturally impacts humidity levels. In many cases, you can reduce dehumidifier usage by increasing air exchange during high humidity periods. Consider these integration strategies:

• Program fans to run at higher speeds during lights-off periods when humidity typically rises
• Position oscillating fans to create movement across the dehumidifier’s intake, improving efficiency
• In sealed grow rooms, coordinate air exchanges with dehumidifier cycles to maintain stable conditions
• Use smart controllers that can manage both ventilation and dehumidification based on sensor readings

For the most advanced setups, environmental controllers can automatically balance the operation of fans, dehumidifiers, humidifiers, and heating/cooling equipment to maintain perfect conditions with minimal energy usage.

Working with Grow Lights and Heat Management

Grow lights generate considerable heat, which directly affects relative humidity – as air temperature increases, its capacity to hold moisture increases, potentially masking humidity issues.

Smart growers coordinate their dehumidification strategy with their lighting schedule:

• Run dehumidifiers at higher settings during lights-off periods when temperatures drop and relative humidity naturally rises
• Position dehumidifiers away from direct light to prevent overheating
• For units inside the tent, synchronize dehumidifier maintenance with light maintenance to minimize disruption
• Consider using infrared thermometers to check for hot spots that might affect local humidity levels

The Spider Farmer model’s external placement with ducting provides a significant advantage here, as it allows you to remove moisture without adding more heat to an already warm growing environment – particularly valuable when using high-output lighting systems.

Frequently Asked Questions

How often should I empty the water collection tank on my dehumidifier?

The frequency depends on your specific humidity levels and dehumidifier capacity. In high-humidity environments, smaller units might need emptying daily, while larger ones with 1-2 gallon tanks might go 2-3 days between empties. For convenience, I recommend setting up continuous drainage when possible. If manual emptying is necessary, check the tank at least once daily until you establish a pattern for your specific setup.

Will running a dehumidifier increase the temperature in my grow tent?

Yes, all dehumidifiers generate some heat during operation. Compressor-based models typically produce more heat than thermoelectric (Peltier) models. For small grow tents where temperature management is already challenging, consider units like the Spider Farmer that can be placed outside the tent with ducting to bring in dry air without adding heat. Alternatively, you might need to adjust your cooling strategy to compensate for the additional warmth.

Can I use a regular household dehumidifier for my grow tent?

While standard household dehumidifiers will remove moisture, they’re not always ideal for grow environments. Grow-specific models offer advantages like external sensors, ducting options, and designs that consider the unique challenges of plant environments. That said, a quality household dehumidifier can work effectively if properly sized for your space, especially if you’re just starting out and want to control costs.

How do I know if my dehumidifier is actually working effectively?

The most reliable method is to use a separate hygrometer (humidity meter) placed at plant level to verify actual conditions. Many growers use multiple hygrometers in different locations to ensure consistent humidity throughout the growing space. You should see a gradual decrease in humidity readings when the dehumidifier is running, and the collection tank should be filling with water (unless humidity was already low). If humidity remains high after 24 hours of operation, your unit may be undersized for the space or require maintenance.

Do I need to run my dehumidifier all the time, or can I use it on a schedule?

Most growers don’t need to run dehumidifiers 24/7. Using a humidity controller or smart plug can automate operation based on actual conditions. Typically, dehumidification needs increase during lights-off periods when temperatures drop (raising relative humidity) and during heavy vegetative growth when plants transpire more moisture. Creating a schedule that anticipates these patterns can save energy while maintaining optimal conditions. Smart models with built-in humidistats will cycle on and off automatically to maintain your target humidity level.

Conclusion

Selecting the right dehumidifier for your grow tent is a decision that directly impacts your plants’ health, growth rate, and ultimate yield. From compact units like the VIVOSUN Small Space Mini Dehumidifier for beginners to commercial-grade powerhouses like the COAIRO 104 Pint model for serious operations, today’s market offers solutions for every growing situation.

The perfect dehumidifier balances capacity, energy efficiency, convenient features, and value – all while meeting the specific needs of your growing environment. The Spider Farmer model stands out for its innovative external placement with ducting, addressing the dual challenges of humidity and heat management. For micro-grows or targeted applications, the Stropum offers precision control in an ultra-compact package.

Remember that humidity management isn’t set-and-forget – plant needs change throughout their growth cycle, and seasonal variations require ongoing adjustments. The investment in a quality dehumidifier with accurate controls pays dividends in healthier plants, reduced disease pressure, and ultimately superior results from your indoor garden.

By applying the knowledge from this guide and matching your dehumidifier to your specific grow tent size and conditions, you’ll create the optimal environment for your plants to thrive. Your attention to this often-overlooked aspect of indoor growing will be rewarded with robust growth, improved yields, and the satisfaction of mastering yet another element of the indoor gardening art.