Best Grow Room Climate Controllers For Optimal Temperature and Humidity


Humidity And Temperature Controller

BEST OVERALL - Inkbird ITC308 Humidity And Temperature Controller


Programmable Digital Timer

MOST AFFORDABLE - Century Programmable Digital Timer


CO2 Monitor Controller

BEST C02 REGULATOR - Titan Atlas 3 Carbon Dioxide (CO2) Monitor & Controller


CO2 Monitor Data Logger

Hydrofarm APCEM2 CO2 Monitor & Data Logger


8 Light Controller

BEST GROW LIGHT CONTROLLER - Titan Controls Helios 12 8-Light Controller

To support a marijuana plant’s life cycle, you need to control four things in a grow room: temperature, humidity, carbon dioxide, and light.

These factors have to be in sync for the whole day, and you can achieve this if you pick the best Grow Room Controllers from our buying guide.

Depending on your growing conditions, you may encounter problems with handling temperature, humidity, carbon dioxide, and light levels.

Is no light getting in? This can impact temperature and humidity levels.

Having problems with CO2 levels? Temperature too high or too low?

Such circumstances can encourage nutrients or molds. Likewise, humidity can affect the growth stages of your plants.

Don’t worry, this product review of climate controllers provides all the information you need about climate controllers for each factor mentioned above.

When growing indoors such as a greenhouse or grow tent, you are in control of your garden’s environment. With the right regulator, all you need is to put temperature and ventilation tools on autopilot.

In this article, you’ll get important control features to make indoor cultivation convenient and simple. By the end of this article, you’ll only need a single controller to perfect Optimal Temperature, Humidity and CO2 level in your marijuana grow room.

Whether you have a modest or a large-sized grow room, the controllers listed below are valuable investments.

These tools will monitor temperature, humidity, carbon dioxide, and light levels. As a result, you can achieve the ideal growing environment.

Best Grow Room Climate Controllers For 2021

1. Top Recommendation: Inkbird ITC308 Humidity And Temperature Controller

Inkbird ITC308 Humidity And Temperature Climate Controller

The Inkbird Combination Humidity Controller IHC200 Temperature Controller ITC308 enables easy connection with refrigeration and heating equipment to control the ideal temperature.

First, the IHC-200 humidistat switches different modes between humidification and dehumidification automatically. It also has humidity control and measuring range of 5% to 99% RH.

Then, the ITC-308 Temperature Controller comes with a temperature control range of -58 to 210 degreesFahrenheit or -50 to 99 degrees Celsius.

You can optimize the high and low temperature alarms when the humidity level goes beyond high or low humidity setting value. The alarm also goes off when there’s a sensor error.

When it comes to versatility, you can use this controller combo for fermenting, home brewing, seed germination, cooking, and meat storage.

More than that, the Inkbird Combination Humidity Controller IHC200 Temperature Controller ITC308 boasts a sensor length of 6.65 feet of 2 meters.

The IHC-200 humidistat has an ambient temperature of -30 to 75 degrees Celsius or -22 to 167 degrees Fahrenheit. Also, it comes with a storage temperature of -30 to 75 degrees Celsius.

This NTC sensor has a storage temperature of -20 to 60 degrees Celsius or -4 to 140 degrees Fahrenheit.

The dual temperature display is one of its best features. One section will show the current temperature while the other one will display the temperature that you have set. Hence, it becomes easier to check the difference.

Furthermore, this combo controller is simple to operate. You’ll only need to use the on and off control for temperature control mode.

The regulator’s plug-and-play design is very user-friendly. We were able to set the cooling and heating differential function individually to protect the tool from violent change.

Overall, the Inkbird IHC200 Controller ITC308 is recommendable when you need simple temperature calibration.

2. Most Affordable And Best In Customization: Century Programmable Digital Timer

Century Programmable Digital Timer

The Century 7 Day Heavy Duty Digital Programmable Timer FD60 U6 is customizable and versatile. The brand is one of the leading manufacturers of premium home improvement goods such as indoor timers.

You can easily set up 8 on and off programs for the timer’s 2 grounded outlets. The good news is that you can control the outlets all together while you can also fix the settings as short as 1 minute.

Likewise, you can select your days, but there’s also the option to use the pre-set combination days.

It has dual outlets that can automate your grow room’s fans and lights. As a result, you won’t experience difficulties in controlling ventilation, which impacts temperature and humidity.

This is because of a program that controls the outlets. A small LED light will notify you if the system is on.

The top asset of the Century 7 Day Heavy Duty Digital Programmable Timer FD60 U6 is its random vacation mode.

You can activate this feature to randomize your programmed lights. It also enables your grow room to look as if you are there even if you are away.

The random security mode will casually postpone the on and off events of lights by 5-30 minutes.

On the other hand, the daylight saving time means there’s no need to reprogram your settings or clock.

You can even prolong the device’s life when you switch to daylight saving mode. Even when there’s a power outage, your settings are still saved.

Meanwhile, the manual override switch helps you turn the timer on and off manually before or after the programmed time.

The digital screen is responsive and reliable. You can see the LED indicator, random mode, and daylight savings time.

For safety, this controller is UL listed with a rating of 115V, 60 Hz, 15A, and 1725W.

Just a head’s up that Century is rebranding to BN-LINK. So, it is possible you’ll get the item either with the brand of Century or BN-LINK. Rest assured that the quality remains the same.

All in all, the Century 7 Day Heavy Duty Digital Programmable Timer FD60 U6 permits you to set your schedules. Thus, there’s no need to turn on and off your tools manually. Simply use the regulator to automate your garden and see how the environment encourages marijuana yield.

Best CO2 Regulators For Your Grow Room

3. Titan Atlas 3 Carbon Dioxide (CO2) Monitor & Controller

Titan Atlas 3 Carbon Dioxide (CO2) Monitor & Climate Controller

The finest thing about the Titan Atlas 3 Carbon Dioxide (CO2) Monitor & Controller is its ability to enrich carbon dioxide through its CO2 exhaust features.

Basically, it controls carbon dioxide from 200 to 2000 parts per million (PPM). Also, it monitors CO2 from 300 to 5000 PPM.

You will see a small CPU-type fan that draws air into the machine. As a result, you get a more accurate reading.

This model can check CO2 levels to prevent carbon dioxide from leaking into other rooms, especially during the night.

The controller can pick up air movement a foot away, which means it has a good sensor. It also comes with a light sensor that automatically turns off for the dark cycle.

During our test, we found that the Titan Atlas 3 Carbon Dioxide (CO2) Monitor & Controller can set the high and low points in increments of 50.

Titan Atlas 3 Carbon Dioxide (CO2) Monitor & Controller

Then, it will turn the carbon dioxide on when the reading drops below the low setpoint and remains on until the level reaches the high setpoint.

The regulator has a plastic enclosure that repels moisture and dust. Having said that, you don’t have to worry about durability.

Therefore, even the moisture inside your grow room can’t damage the controller. Besides, the model has a 3-year warranty.

Unfortunately, you can’t calibrate the device for accuracy. However, we were able to program this unit to turn on exhaust fans when the CO2 level exceeded our set minimum.

In conclusion, the Titan Atlas 3 Carbon Dioxide (CO2) Monitor & Controller is suitable for cannabis growers who want enrichment and exhaust features. In this way, you get to deliver ideal conditions for plant growth.

4. Hydrofarm APCEM2 CO2 Monitor & Data Logger

Hydrofarm APCEM2 CO2 Monitor & Data Logger

You can depend on the Hydrofarm APCEM2 Autopilot Desktop CO2 Monitor & Data Logger to show variable readings of temperature, relative humidity, and carbon dioxide levels. Do you want every minute reading? You got it! Every hour, every day, or every week—the regulator can do it.

What sets this unit apart from the other CO2 controllers is its ability to provide a trend for your settings. For example, the data logger can calculate the timeframe you created in the past 5 days.

Similarly, the regulator comes with a digital memory chart of recorded carbon dioxide, temperature, and relative humidity readings over an adjustable 7-day or 24-hour period.

Therefore, it is able to provide a report and basis for your future settings.

First, select your desired zoom level. Afterward, enable the LOG to see all the parameters’ measurements for each division.

Note that the APCEM2 desktop CO2 Monitor is patent pending. It is a hook-and-loop fastener along the tool’s back. This feature can securely fasten a rectangular external battery pack.

It also has a built-in directory of common plant types, along with the plants’ general carbon dioxide requirements. If your plant is not included, there are 2 slots for custom plant inputs.

Moreover, the Hydrofarm APCEM2 Desktop CO2 Monitor  has a two-channel low drift non-dispersive infrared gas sensor.

Like most controllers, this comes with an audible alarm to notify you about low and high carbon dioxide readings. Because of its clear display with 3 multicolored LEDs, you can see every important setting and information.

When it comes to flexibility, its green power supply is compatible with a standard smartphone charger.

A bit of trivia – Hydrofarm is one of the oldest manufacturers of hydroponics and aquaponics equipment. You can guarantee that this tool is UL-listed and can serve you for many years.

In a nutshell, the Hydrofarm APCEM2 Autopilot Desktop CO2 Monitor & Data Logger is an asset for every marijuana grow room. It combines innovation, accuracy, and affordability into a compact, user-friendly carbon dioxide monitor.

Best Grow Light Controllers

5. Titan Controls Helios 12 8-Light Controller

Titan Controls Helios 12 8-Light Controller

We’ve tried 5 of the best light controllers, and it was easy to choose the Titan Controls Helios 12 8-Light Controller as the winner.

This is mainly because of its dual relay trigger cord that can set 24-hour wall timers to operate your grow lights. Also, it can operate 8 HID lights at 240V.

The model boasts about being the only lighting controller that comes with 2 industrial-grade ballast rated relays. But since there are dual trigger plugs, you’ll need 2 timers to activate all 8 outlets.

Because of the unit’s plastic enclosure, moisture and dust can’t trouble you. When you see the set-up, you’ll notice that it has a safer electrical set-up than other models.

The main problem we encountered was not having the right screw size to attach the metal mount to the Titan Controls Helios 12 8-Light Controller.

Remember that this is advisable for those who want to control lights.

Thus, you will need a separate outlet if you need to regulate inline fans.

You should also know that the access panel to hard wire the unit is found on the back of the controller. Yet, it remains easy to install the tool.

Also, the unit can save a lot of bulbs because of its multi-tap outlets that permit total flexibility. Similarly, the tool transfers the power better upon initial startup.

It also creates sequences for your ballasts, so you can avoid a massive amp surge. Therefore, your ballasts become cooler when running with this regulator.

All in all, the Titan Controls Helios 12 8-Light Controller is an amazing regulator because of its simplicity, quality, and price.

Bonus Product: All-In-One Grow Room Controller

6. Autopilot APC8200 CO2 Monitor & Controller With Memory

Autopilot APC8200 CO2 Monitor & Climate Controller With Memory

The Autopilot APC8200 CO2 Monitor & Controller with Memory is a fully customizable unit that provides flexibility in programming CO2 levels.

It also has a trend chart that can record carbon dioxide readings every minute, hourly, daily, and weekly for precise analysis of CO2 distribution. Hence, the memory feature provides growers a real edge in fine-tuning the grow room environment.

Likewise, the adjustable trend chart zoom levels allow you to trace PPM levels. The 2-channel low drift NDIR sensor also helps with this.

It’s also worth knowing that the Autopilot APC8200 CO2 Monitor & Controller saves environmental data up to 12 months.

It can shut down the CO2 generator when it reaches setpoint PPM.

Autopilot APC8200 CO2 Monitor & Controller With Memory

For example, there’s a margin of 100 if your setpoint is 800. Thus, the regulator will turn on at 750 PPM, but will shut down at 850 PPM.

Additionally, the remote carbon dioxide sensor probe with photocell has a 15-inch data cable. This feature lets you take readings from proper grow room locations.

You can rely on the Green LED identification lights for the unit’s status at all times. Don’t worry because the identification lights won’t harm your cannabis plants.

Besides, the photocell on the PPM reader allows the system to run even when the lights go off.

To sum it up, the Autopilot APC8200 CO2 Monitor & Controller with Memory provides a simple and affordable way to monitor, record, and control CO2 levels over an adjustable period. Its fully customizable CO2 setpoint and deadband can adjust and review your CO2 levels.

Quick Recommendation

If you need a compact temperature and humidity regulator, then you should go for the Inkbird Combination Controller. The Century 7 Timer is a bit heavier, but they both have excellent sensors and control settings.

For CO2 regulators, the Titan Atlas 3 is very lightweight, but it doesn’t have the data log features of the Hydrofarm APCEM2. However, they both have accurate readings and control features.

We’ll only suggest the Titan Controls 8-Light Controller for all your lighting woes because of its ability to save your bulbs in the long run.

Finally, the Autopilot APC8200 is a great pick in terms of customizing CO2 setpoint and deadband.

They are good options, yet they all have unique features that can win you over. So, better learn how to control growing conditions first. Then, see which model is most suited for the job.

Steps To Perfecting Grow Room Climate Control

Temperature Controls

Temperature is crucial for the rapid growth and proper development of marijuana.

Your marijuana garden will need optimum temperature and humidity levels to thrive.

Cannabis plants grow best at temperatures between 20 and 25 degrees Celsius (67 and 77 degrees Fahrenheit). However, here’s a rule of thumb for temperature settings:


Temperature Levels

Seedlings or Cloning

74-77 degrees Fahrenheitno temperature drop at night

Flowering or Vegetative

75-85 degrees daytime Fahrenheit

65-75 degrees Fahrenheit nighttime


65-80 degrees Fahrenheit daytime

60-75 degrees Fahrenheit nighttime

As you can see, it’s preferable to keep your cannabis at the higher end of the temperature spectrum during the seedlings or cloning phase.

Furthermore, it is better to go for the lower end of temperature levels during flowering.

Higher temperatures allow young plants use their leaves to absorb more moisture out of the air when they are developing their root system.

Additionally, cooler temperatures reduce the risk of mildew and mold inside moist buds. This is especially helpful in keeping leaves from growing too bushy.

In conclusion, remember 2 important things:

  • Cannabis plants will not grow to their full potential if your grow room is kept too cold.
  • Marijuana plants may grow spindly if your grow room is too hot.

Temperature Controls

Generally, temperature and humidity work hand in hand. They also benefit from humidity conditions between 40% and 70%.

However, such factors would still depend on the growing stages:


Humidity Levels

Seedlings or Cloning

65% to 70%

Flowering or Vegetative

40% to 50%


30% to 40%

Meanwhile, it is advisable to gradually tone down humidity levels when you are shifting from the vegetative to flowering stage.

A week or two before harvest, you should decrease humidity levels even more. A controller can make this adjustment easy for you.

When you control humidity in a grow space, you help plants keep a high intake of water and nutrients.

Nevertheless, you have to be careful because humidity below 30% will urge the plants to become dormant. This is marijuana’s way of preventing dehydration.

Moreover, relative humidity is how much moisture is in the air at a given temperature, compared to how much the air could potentially hold at that temperature.

So, if your grow space is at 90 degrees and the RH level is 60%, this means the air is 60% full of moisture.

If humidity levels in a grow room are too low, plants may not be able to get any moisture through their leaves. As a result, your garden may end up drinking too much nutrient solution.

Subsequently, cannabis may suffer from nutrient burn, which can cause wilted leaves with brown edges.

If the leaves become crunchy and dry out, your yield can greatly diminish.

High humidity levels can cause the formation of mildew and mold during your garden’s flowering stage.

If you smell or see any mold, it means plants are ruined and you need to throw them away immediately.

Therefore, you must improve ventilation using fans or dehumidifier to decrease humidity.

But when you need to ramp up humidity levels, then you must increase the temperature with less ventilation or more lighting. Also, a misting humidifier can add moisture to the air.

What CO2 Can Do For Your Grow Room

Grow System

We all know that plants need carbon dioxide to grow and survive. Nonetheless, providing additional carbon dioxide in a grow room can radically increase marijuana yield.

Fresh air delivers CO2 at about 370 PPM. The tricky part is ensuring sufficient ventilation and air movement because plants take in CO2 quickly.

How Much Co2 Does A Grow Room Need?

Levels of CO2 below 200 PPM can limit cannabis growth, whereas 100 PPM will hinder growth.

But if your controller can increase the levels to 750 to 1,500 PPM, your yields can increase by 30% to 50%. You may even reduce flowering and fruiting stages by 7 to 10 days.

However, levels beyond 1,500 PPM are wasteful. Meanwhile, 5,000 PPM and above are detrimental. Unwarranted levels will cause the stomata to close, momentarily halting photosynthesis.

This is where a controller shines. A regulator’s photocell senses when the lights are off. Then, the controller will turn off the carbon dioxide at night when plants only use oxygen.

The device will also match up carbon dioxide supplementation with temperature and humidity control. The controller can turn on exhaust fans when temperature or humidity levels go beyond setpoints.

Besides, the monitor alerts the controller to turn the carbon dioxide on if CO2 levels drop below a minimum setpoint. Therefore, you have total and accurate control over CO2 levels.

Light Controls

You can increase the ventilation or use LED lights when you need to cool down your grow space.

Meanwhile, you can switch to HID lights or put extra LED lights if you need to make the space warmer.

But when you have a light controller, it’s simple to set up multiple lights inside a grow room. You’ll gain the ability to turn several lights on and off all at once.

Likewise, you can program different times depending on your desired parameters.

Ergo, temperature, humidity, carbon dioxide, and light work together to make a bountiful yield. You can have the power to manage all of them if you have the right grow room controller.

How To Pick The Best Grow Room Controllers

Checking Grow Room Controller

Customization And Data Storage

Your main reward when using regulators is the power to manage your grow room environment automatically.

The 6 units above can customize your settings. But the Hydrofarm APCEM2 Autopilot Desktop CO2 Monitor & Data Logger and the Autopilot APC8200 Monitor & Controller are the ones that have trend data storage.


The best unit must come with an easy-to-see digital display. Hence, it becomes easy to check the temperature and humidity you have set. All of the products in this post have user-friendly displays.


A good controller will produce a loud sound to inform you if the temperature or humidity has exceeded or gone below your desired threshold.

The Hydrofarm APCEM2 and Inkbird Combination have the best alarm features.

Ease Of Use

Having a user-friendly design varies, but the design should enable you to set the temperature or lighting levels without too much manual labor.

Some models come with a direct plug, but with a separate timer. Meanwhile, other units come with a daisy chain configuration that allows plugging the timer into the controller.


Make sure that your controller is made of long-lasting materials. The enclosure or case is often made of plastic.

When your regulator is durable, it will be able to protect itself from external factors that can damage internal components.


1 Year Warranty Logo

Most of the options that we have listed down in this post have a warranty that lasts from one to three years.

It is good to have growing tools that have a longer warranty against defect. This will give you confidence about the quality and durability of an equipment.

Marijuana Grow Room Controllers FAQ Section

Why Controllers Matter

In reality, your plants can survive by relying on your growing skills. Yet, regulators are excellent investments when you want to boost success in cultivating cannabis. Similarly, controllers are a great assurance that your plants will not die.

Naturally, your cannabis plants will suffer when the temperature or the humidity is above or below the right levels.

In this way, diseases and pests can hinder growth. When your plants die, your yield will also suffer.

If your grow room temperature is too high, the air might hold more water vapor. Also, humidity levels will go up when the air moves fast. Consequently, your plants get sticky.

On the other hand, there will be less water vapor when the temperature is low. Hence, the humidity level will also be lower.

More than that, rotting is possible if there are too much moisture and humidity. If white mold develops on the leaves, your cannabis yield might be at risk.

High levels of humidity could also stop your plants from receiving carbon dioxide, which is important for its growth. Subsequently, it will be hard for the plants to undergo photosynthesis.

Meanwhile, too little humidity might encourage stagnant growth. This will prevent your marijuana plants from getting the necessary nutrients to survive.

Take Total Control Over Your Cannabis Grow Room Conditions

Similar to us, humans, plants need the right temperature, humidity, and lighting levels to survive.

Grow rooms create an artificial environment for your garden. Yet, they can isolate your plants from the outside world.

Each controller on this list has its unique feature that can improve the environment of your marijuana grow room.

Consider your conditions first and weigh them against the factors and features to see which model suits you best.

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.