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Best CO2 Regulators for Growing Cannabis

CO2 Can Be Your Friend

When you want professional quality marijuana, or when you have a large grow operation, you need a CO2 generator setup. Using dry ice, fermentation, or mushroom boxes just isn’t enough. You can’t wait for global warming and rising carbon dioxide levels to save the day, either.

CO2 Regulators Reviewed Here

GROW1 CO2 Grow Room Environment Regulator Flow Meter Solenoid
SPL Co2 Regulator Emitter System with Solenoid Valve Accurate and Easy to Adjust Flow Meter Made of High Quality Brass - Shorten up and Double Your Time for Harvesting!
Day and Night CO2 Monitor and Controller for Greenhouses
CO2 Generator - Liquid Propane LP - Autopilot APCG8LP
Intermatic P1121 Heavy Duty Outdoor Timer 15 Amp/1 HP for Pumps, Aerators, Heaters, Holiday Decorations and Landscape Lighting
GROW1 CO2 Grow Room Environment Regulator Flow Meter Solenoid
SPL Co2 Regulator Emitter System with Solenoid Valve Accurate and Easy to Adjust Flow Meter Made of High Quality Brass - Shorten up and Double Your Time for Harvesting!
Day and Night CO2 Monitor and Controller for Greenhouses
CO2 Generator - Liquid Propane LP - Autopilot APCG8LP
Intermatic P1121 Heavy Duty Outdoor Timer 15 Amp/1 HP for Pumps, Aerators, Heaters, Holiday Decorations and Landscape Lighting
$89.99
$37.99
$199.00
$379.99
$21.85
-
4 Reviews
13 Reviews
120 Reviews
-
1,208 Reviews
-
-
GROW1 CO2 Grow Room Environment Regulator Flow Meter Solenoid
GROW1 CO2 Grow Room Environment Regulator Flow Meter Solenoid
$89.99
4 Reviews
-
SPL Co2 Regulator Emitter System with Solenoid Valve Accurate and Easy to Adjust Flow Meter Made of High Quality Brass - Shorten up and Double Your Time for Harvesting!
SPL Co2 Regulator Emitter System with Solenoid Valve Accurate and Easy to Adjust Flow Meter Made of High Quality Brass - Shorten up and Double Your Time for Harvesting!
$37.99
13 Reviews
Day and Night CO2 Monitor and Controller for Greenhouses
Day and Night CO2 Monitor and Controller for Greenhouses
$199.00
120 Reviews
CO2 Generator - Liquid Propane LP - Autopilot APCG8LP
CO2 Generator - Liquid Propane LP - Autopilot APCG8LP
$379.99
-
-
-
Intermatic P1121 Heavy Duty Outdoor Timer 15 Amp/1 HP for Pumps, Aerators, Heaters, Holiday Decorations and Landscape Lighting
Intermatic P1121 Heavy Duty Outdoor Timer 15 Amp/1 HP for Pumps, Aerators, Heaters, Holiday Decorations and Landscape Lighting
$21.85
1,208 Reviews

CO2 Accessories Reviewed Here

Cyl-Tec 20 lb CO2 Tank - Aluminum Cylinder with CGA320 Valve and Carry Handle
AcuRite 00613 Indoor Thermometer & Hygrometer with Humidity Gauge, 3" H x 2.5" W x 1.3" D
Amflo 24-25E-RET 1/4" X 25' Polyurethane Recoil Air Hose is Lightweight, Non-Marring, Flexible in Extreme Cold, and Stores Itself When Not in Use - Ideal for Home, Shop, or Industry
The Exhale Homegrown CO2 365 - Self-Activated Bag for Grow Rooms & Tents with Hanger & THCity Gloves
Cyl-Tec 20 lb CO2 Tank - Aluminum Cylinder with CGA320 Valve and Carry Handle
AcuRite 00613 Indoor Thermometer & Hygrometer with Humidity Gauge, 3" H x 2.5" W x 1.3" D
Amflo 24-25E-RET 1/4" X 25' Polyurethane Recoil Air Hose is Lightweight, Non-Marring, Flexible in Extreme Cold, and Stores Itself When Not in Use - Ideal for Home, Shop, or Industry
The Exhale Homegrown CO2 365 - Self-Activated Bag for Grow Rooms & Tents with Hanger & THCity Gloves
$109.00
$9.88
$15.84
$38.95
90 Reviews
16,016 Reviews
296 Reviews
127 Reviews
-
Cyl-Tec 20 lb CO2 Tank - Aluminum Cylinder with CGA320 Valve and Carry Handle
Cyl-Tec 20 lb CO2 Tank - Aluminum Cylinder with CGA320 Valve and Carry Handle
$109.00
90 Reviews
-
AcuRite 00613 Indoor Thermometer & Hygrometer with Humidity Gauge, 3" H x 2.5" W x 1.3" D
AcuRite 00613 Indoor Thermometer & Hygrometer with Humidity Gauge, 3" H x 2.5" W x 1.3" D
$9.88
16,016 Reviews
Amflo 24-25E-RET 1/4" X 25' Polyurethane Recoil Air Hose is Lightweight, Non-Marring, Flexible in Extreme Cold, and Stores Itself When Not in Use - Ideal for Home, Shop, or Industry
Amflo 24-25E-RET 1/4" X 25' Polyurethane Recoil Air Hose is Lightweight, Non-Marring, Flexible in Extreme Cold, and Stores Itself When Not in Use - Ideal for Home, Shop, or Industry
$15.84
296 Reviews
The Exhale Homegrown CO2 365 - Self-Activated Bag for Grow Rooms & Tents with Hanger & THCity Gloves
The Exhale Homegrown CO2 365 - Self-Activated Bag for Grow Rooms & Tents with Hanger & THCity Gloves
$38.95
127 Reviews

Waiting for Climate Change?

Right now, CO2 levels are at about 400 parts per million. You may have seen weed growing blogs and magazines quoting it as 350 PPM, but that’s data from years ago. If you want to know the current statistic, check out this page. Levels go up or down by about 10 PPM depending on the time of year, but yes, climate change is real, people.

When you grow cannabis, you can raise the amount of carbon dioxide in the air to nearly 1500 PPM and your weed will flourish. You’ll have up to 30% more buds at harvest time if you add CO2 to the air. Go over that amount, and it will suffocate and die.

Quick note: before we move on, if you’re going to add carbon dioxide to your plants’ air, use ventilation.  Move the air around in your grow space.

Generators, regulators, and controllers, oh my!

You can purchase an all-in-one ready-to-use CO2 generator, or you can buy parts separately and put together your own system. You’ll need a source of carbon dioxide and a way to control its release into your grow room or greenhouse.

Some all-in-one systems burn propane or butane to release CO2. If you don’t want to add extra heat and humidity into your plants’ environment, you can use a tank of carbon dioxide plus a controller and regulator. The controller senses the amount of PPM in the environment. The regulator controls the release of CO2 from the tank.

How much carbon dioxide do you need?

It’s safest if you invest in a controller that can sense CO2 levels in your grow room. Simply using a tank and a regulator means you’re guessing whether it’s enough or too much. That said, a rough estimate here might help you:

  • Check the CFH rating (cubic feet per hour) if you have a generator.
  • Measure the size of your grow tent to get the cubic volume (length x width x height).

If you’re using a tank of CO2 like you’d buy for MIG welding, you can set the same amount of flow rate. Again, it’s smart to have a controller, and a timer, too. Plants only use carbon dioxide during the daytime, not at night.

  • A pound of carbon dioxide compressed in a tank is equal to about 8.7 cubic feet of gas once it’s released into the air
  • Take the cubic size of your grow room and multiply it by .0015 (or .0013 PPM if you want to play it safe) to find out how much flow you need
  • Set the regulator for the correct amount of PSI and flow rate
  • Set the timer to have the gas released as desired

Here’s some sample math:

  • Your room measures 8 by 8 by 8, so that’s 512 ft
  • 512 x .0013 = 0.6656 or about 0.66 cubic feet
  • You can set the regulator for 100 PSI with flow at 0.33 cubic feet per minute (20 CFH)
  • Let gas flow for 2 minutes and you’re done
  • Repeat every couple of hours while your grow lights are lit

Why is a timer also important?

Because breathing in too much CO2 isn’t good for humans. You don’t want to be hanging out in your grow room when your system is releasing the gas into the air. Unlike a generator that burns propane or other natural gas fuel, using a tank and regulator means you’ll be injecting gas into the air for a couple of minutes every couple of hours. You don’t need to let it run for long periods of time. It’s actually a pretty cheap solution.

Intermatic P1121 Heavy Duty Outdoor Timer 15 Amp/1 HP for Pumps, Aerators, Heaters, Holiday Decorations and Landscape Lighting
1,208 Reviews
Intermatic P1121 Heavy Duty Outdoor Timer 15 Amp/1 HP for Pumps, Aerators, Heaters, Holiday Decorations and Landscape Lighting
  • Designed specifically for outdoor applications, dynamic weather conditions and ease of use
  • Controls pool pumps, water fountains, yard/patio/landscape/holiday/LED/CFL lighting, signs, fans, engine block heaters, heavy duty appliances and more
  • To use, insert a green pin for the start time and a red pin for the end time
  • Ships with 2 sets of pins for 2 ON/OFF settings per day, and a grounded 3-prong plug and receptacle
  • Ratings: 15 A, 1,800 W, 120 V, 60Hz - CSA Certified, 1 Year Warranty
  • Has a manual override ON/OFF switch, a waterproof cover and a 12-Inch grounded cord

Now we’ll review the top regulators here below so you can get the best one for your system

The top CO2 regulators

We’ll begin with the ones that have solenoid valves.

GRO1 CO2 Grow Room Environment Regulator Flow Meter Solenoid

GROW1 CO2 Grow Room Environment Regulator Flow Meter Solenoid
4 Reviews
GROW1 CO2 Grow Room Environment Regulator Flow Meter Solenoid
  • - 6 ft long 13-prong grounded power cord and plug to 120V, 60Hz household outlet
  • - Solenoid valve (precise 0.5-15 CFH settings)
  • - Pressure gauge, brass alloy body, tank pressure gauge
  • - 5 meter long black 1/4" tubing
  • - 2 plastic white washers

The CO2 Grow Room Environment Regulator is a popular one for people who grow plants in aquariums, but it’s also ideal for growing pot. The flow meter adjusts between 0.5 and 15 cubic feet per hour and it has a pre-set regulator and a durable solenoid valve. It’s covered by a factory warranty.

SPL Co2 Regulator Emitter System with Solenoid Valve and Flow Meter Made of High Quality Brass

SPL Co2 Regulator Emitter System with Solenoid Valve Accurate and Easy to Adjust Flow Meter Made of High Quality Brass - Shorten up and Double Your Time for Harvesting!
13 Reviews
SPL Co2 Regulator Emitter System with Solenoid Valve Accurate and Easy to Adjust Flow Meter Made of High Quality Brass - Shorten up and Double Your Time for Harvesting!
  • 1.58¡± high pressure gauge
  • Flowmeter: 0-15 scfh
  • Inlet connection: cga-320
  • Hose tail: suit for 4.2 mm inside diameter hose

SPL touts their all-brass regulator because it’s precise and durable. They know their product’s good for growing weed because they point out that fact. It comes with a flow gauge that can release between 0.5 and 15 CFH (same as the GRO1 described above). It’s rated for 0 to 4000 PSI.

The 6-foot power cord needs to be connected to 110V electricity (sorry folks outside North America). It also comes with 10 feet of ¼-inch air hose so it connects directly to a 20 or 50-pound CO2 tank.

Get this controller because you need control

Really, it’s so nice to have something monitoring your CO2 levels.

CO2Meter RAD-0501 Day Night CO2 Monitor and Controller for Greenhouses, Grey

Day and Night CO2 Monitor and Controller for Greenhouses
120 Reviews
Day and Night CO2 Monitor and Controller for Greenhouses
  • Controls CO2 in greenhouses or growrooms.
  • Built-In light sensor allows CO2 enrichment only during daylight hours.
  • Piggy back plug allows for control of CO2 generator or regulator (sold separately).
  • User can set desired CO2 level for different plants.
  • Easiest CO2 controller to use in the industry.

Use this CO2 Monitor to keep an eye on gas levels in your grow room. Mount it inside your setup and plug it into electricity and your regulator. It automatically shuts down your flow when it’s dark because it has a light sensor, or when levels reach your desired preference for PPM. In fact, you can be quite picky over CO2 PPM with this controller because it’s adjustable in 50 PPM increments from 100 to 9950.

Ready-made CO2 generator

Maybe you don’t want to build your own setup, maybe you don’t want to have to haul around heavy canisters of gas, maybe you need a little more heat and humidity in your grow room. (Do be careful about getting it too rainforesty in there.)

CO2 Generator – Liquid Propane LP – Autopilot APCG8LP

CO2 Generator - Liquid Propane LP - Autopilot APCG8LP
  • Dual solenoid valves
  • Precision manufactured brass burners
  • Solid state electronic ignition module - no pilot light necessary
  • TIP OVER switch shuts off gas source if the unit falls or tips over
  • Backed by Hydrofarm's manufacturer warranty!

Autopilot’s APCG8LP is a powder-coated steel enclosure that burns propane or natural gas to add carbon dioxide to the air. Keep in mind this is made for grow rooms larger than 14 by 14 feet. It could raise the temperature up to 10 degrees higher while it runs.

It has a safety features that turns it off if it tips over. It’s smart to use a controller to make sure it runs only when it’s needed. It can put out up to 22 cubic feet per hour.

A few accessories for use with your regulator

If you don’t burn natural gas to make CO2 , you need another source. Why not have your canisters of carbon dioxide delivered right to you instead of hauling these heavy babies around in your car?

Cyl-Tec 20 lb CO2 Tank – New Aluminum Cylinder with CGA320 Valve

Cyl-Tec 20 lb CO2 Tank - Aluminum Cylinder with CGA320 Valve and Carry Handle
90 Reviews
Cyl-Tec 20 lb CO2 Tank - Aluminum Cylinder with CGA320 Valve and Carry Handle
  • The Cyl-Tec 20lb CO2 tank ships ready to fill (empty). Federal law requires that the tank ship unfilled. Once filled this tank will be able to dispense 20-25 beer kegs. This tank can be used for other applications including hydroponics, sodastream refills, etc
  • Certified for use in the U.S.(DOT) and Canada (T.C.). The tank is stamped with these markings.
  • This tank has 1800 PSI service pressure.
  • Made from high quality 6061-T6 brushed aluminum to ensure durability. Aluminum tanks will not rust as steel tanks do over time
  • Includes durable carry handle to make transportation easier. Also includes new brass CGA 320 CO2 valve. 320 valves are approved by the Compressed Gas Association (CGA) and have a male thread for CO2 regulators.

This 20-pound tank of carbon dioxide will help you grow, and it can also carbonate your beverages. It keeps the gas at 1800 PSI, has a carrying handle, and a brass CGA 320 C)2 valve with a male thread ready for a regulator.

AcuRite 00613 Indoor Humidity Monitor

AcuRite 00613 Indoor Thermometer & Hygrometer with Humidity Gauge, 3' H x 2.5' W x 1.3' D
16,016 Reviews
AcuRite 00613 Indoor Thermometer & Hygrometer with Humidity Gauge, 3" H x 2.5" W x 1.3" D
  • Digital Thermometer | Monitor indoor temperature (°F/°C) & humidity
  • Hygrometer | Humidity gauge allows you to keep an eye on home health and comfort - LOW, HIGH, OK
  • Multifunctional | Fold-out stand & clip with magnetic backing for mounting to your refrigerator
  • Accurate | Each thermometer is pre-calibrated for precise temperature and humidity measurement
  • Support | 1 Year Warranty and US-based customer support team

It’s always a good idea to keep an eye on the temperature and humidity levels in your grow tent. This one’s battery-operated, easy to read, and wireless.

Amflo 24-25E-RET Blue 120 PSI Polyurethane Recoil Air Hose 1/4″ x 25′ With 1/4″ MNPT Swivel Ends And Bend Restrictor Fittings

25%
Amflo 24-25E-RET 1/4' X 25' Polyurethane Recoil Air Hose is Lightweight, Non-Marring, Flexible in Extreme Cold, and Stores Itself When Not in Use - Ideal for Home, Shop, or Industry
296 Reviews
Amflo 24-25E-RET 1/4" X 25' Polyurethane Recoil Air Hose is Lightweight, Non-Marring, Flexible in Extreme Cold, and Stores Itself When Not in Use - Ideal for Home, Shop, or Industry
  • Amflo's Polyurethane recoil hose retains its self-coiling properties and stores itself when finished - no more wasting time coiling your hose for storage
  • Smooth, non-marring finish is ideal for indoor trim work where scratching surfaces could cause damage to painted surfaces, wood flooring and trim, and laminates
  • Braided nylon reinforcement and oil and chemical resistance make this hose a great choice for harsh environments like automotive repair shops and industrial facilities
  • Due to very good cold weather flexibility, polyurethane hose is perfect for year round use in temperatures as low as -30 degrees F
  • Features: 1/4 inch NPT swivel fittings to reduce twisting, rugged PVC bend restrictors prevent damage to hose ends, 120 PSI working/480 PSI burst pressure, -30 to +150 temperature range

This is an air hose that stays neatly coiled and out of your way.

Exhale 365 – Self Activated Co2 Bag Homegrown for Grow Rooms & Tents

The Exhale Homegrown CO2 365 - Self-Activated Bag for Grow Rooms & Tents with Hanger & THCity Gloves
127 Reviews
The Exhale Homegrown CO2 365 - Self-Activated Bag for Grow Rooms & Tents with Hanger & THCity Gloves
  • ExHale 365 is a self-activated version of the Original CO2 Bag.
  • The 365 will provide a 4x4 foot or 128 cubic foot space with CO2 for 9 months of which 6 months are peak production
  • Directions: Remove hanger from bag. allow the material in the upper spawn pod to fall to the sterilised substrate below by gently moving the spawn pod down to the lower part of the bag. Re-attach the separation seam hanger by placing it above the filter patch. The Exhale bag can now be placed in your garden.
  • Full production will be reached within 30-45 days. The Exhale 365 will produce CO2 for 9 months.
  • THCity Gloves Included

Nothing wrong with baby steps! If you have a little grow room not more than 4 by 4 feet in size, you can still add CO2 to the air with this bag from ExHale. It lasts up to 6 months. Just hang it a little higher than your plants.

CO2 is Your Friend (Sometimes)

Using carbon dioxide to reap a larger harvest of cannabis is smart. It’s also not hard to do. Building your own setup with a tank, regulator, and controller is easy. Check back soon for more reviews of the best products for raising healthy weed.

And if you still need to complete your ventilation setup, check out our round up of the best inline fans for growing marijuana.

Last update on 2019-11-14 / Affiliate links / Images from Amazon Product Advertising API

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