Top 15 Best CO2 Diffusers in 2023

Keeping aquatic pets is a lot different from other domestic animals. While you have to provide a suitable home (aquarium), you also must strive to provide the necessary conditions to support survival. With the best CO2 diffuser, you can increase the surface area to ensure carbon dioxide is readily available.

Plants use up carbon dioxide in the water and release oxygen. If you have a planted tank set up, too much gas could be unfavorable for your plants and animals. Having a gas CO2 diffuser could be useful, no matter your aquarium size or nature of the setup.

Do I Need A CO2 Diffuser In My Aquarium?

Just as it will be impossible for humans to survive without oxygen, fish also need CO2 for their survival. In an aquarium, it can be quite challenging to maintain gas levels at an optimum. It is for this reason you want to invest in the best CO2 diffuser.

With the gas levels in check, you can be confident that plants won’t burn out, and you won’t find dead fishes floating around. It could take a while for carbon to circulate throughout the system in a water medium. A steady increase in the surface area could make it easy for the gas to get around quickly.

Are CO2 Diffusers Good For Planted Tanks?

You can use a gas spreader in both a real and an artificial plant aquarium. Since live plants need more carbon dioxide to promote photosynthesis, gas levels need to be monitored in an actual plant setup. Any good quality product should be safe to use in a real or fake plant tank. You need to ensure that it works for your aquarium size.

How Does A CO2 Diffuser Work?

A gas diffuser works by increasing the surface area of the water exposed to CO2. It does this by slowing feeding the gas through a ceramic disc, which distorts the water and ensures that carbon dioxide remains in circulation for plant conversion to oxygen. You can check this video to learn more about the CO2 diffuser.

Can I Use A CO2 Diffuser In Any Water?

A gas diffuser can work in an aquarium irrespective of whether you have a freshwater or saltwater setup. Since the main aim is to increase the surface area to encourage the spread of carbon dioxide, you should not worry about using a diffuser.

CO2 Diffusers Vs. Reactors

Aside from the fact that diffusers and atomizers work well in small and medium tanks, while reactors are best for extra-large aquarium, there are other differentiating factors apart from their accommodating tank size. It is easy to whip together a DIY reactor, but except you are skilled with glass or ceramic, it may be tricky to make an aquarium gas diffuser.

They perform the same action, and the only difference is in the mode of operation. Reactants make use of the water pressure to absorb CO2 into the system. On the other hand, diffusers work by producing tiny bubbles that provide carbon dioxide for marine life to consume.

Different Types Of CO2 Diffusers

As you imagined, not all CO2 diffusers are the same. They differ mainly based on their design and mode of setup. The common ones are the ones that feature a ceramic glass. They are easy to operate, maintain, and also less compared to the other types.

The main types of carbon dioxide aquarium diffusers are:

Ceramic Glass CO2 Diffuser

They are lightweight and include a suction cup for secure attachment to the tank. The narrow design of the tubing makes it safe for systems that require tiny bubbles. You could also consider these if you are looking to spend less on new tank gear.

CO2 Reactor

You could also find diffusers with a reactor that promotes high power diffusion. They are more expensive than other types and are best for large tanks that hold up to 100 gallons.

In-line Diffuser

The in-line diffuser is designed for use with a canister filter. They are best for large surface area diffusion. So they are not a good choice for a small size tank.

Best CO2 Diffuser Comparison Chart 2023

You will find a quick breakdown of some of the critical features of 15 of the best carbon dioxide gas diffusers in the table below. There is a more detailed review afterward.

Which Are The Best CO2 Diffusers To Buy?

Before I get into the review proper, here is a quick rundown of 15 gas diffusers with their best labels. You could easily find one that met your preference and read more in the section below.

• Best Overall – JARDLI Pollen Glass CO2 Diffuser
  “This JARDLI Pollen Glass diffuser comes with a U-shaped connecting tube which helps with CO2 diffusion. It comes with two suction cups and a 1.5-inch diameter, which is great for 30 to 50-gallon tanks.”
• Best Budget – S.T International Aquarium CO2 Diffuser
  “The S.T International gas diffuser is best for small to a medium-sized tank that holds less than 30 gallons. The solenoid valve and safety valve give you control over the system at every interval.”
• Best for Nano Tank – JARDLI Pollen Glass + Bubble Counter CO2 Diffuser
  “Built for 20-gallon tanks and under, the JARDLI CO2 diffuser with bubble counter is best for small-sized aquariums. Gas is evenly circulated via the ceramic membrane, and the glass design makes it capable of blending into any setup.”
• Best for Large Aquarium – Fibst Aquarium CO2 Diffuser
  “With the ability to work in an 80-gallon tank, the Fibst CO2 diffuser is best for use in a large aquarium. It is made of stainless steel, making it highly durable and a good option if you are shopping for quality.”
• Best for 55 Gallon – Yagote Glass CO2 Diffuser
  “The Yagote gas diffuser is my best pick if you want a product that meets all your expectations. It can be used in a 55-gallon aquarium set up and is easy to install and maintain.”
• Best JARDLI – JARDLI Music Glass CO2 Diffuser
  “With a visually appealing design, the JARDLI Music Glass diffuser could be the best pet gift you have given yet. Although the two-inch diameter makes it best for large tanks, you can’t ignore the handcrafting of this quality carbon dioxide diffuser glass.”
• Best for Fish Tanks – STARSIDE Aquarium CO2 Diffuser
  “The U-shaped design of the STARSIDE Aquarium CO2 diffuser makes for a highly durable device that is easy to setup. The resin glass can withstand everyday use and can survive in up to 60 gallons of water.”
• Best Versatile – Bluecell Aquarium CO2 Diffuser
  “This durable and straightforward U-shaped CO2 diffuser from Bluecell provides the system with suitable pressure and maintains carbon dioxide levels in the aquarium. It is best for use in a 30 to 50-gallon water tank.”
• Best In-line – NilocG Aquatics CO2 Diffuser
  “The in-line design allows for a secure connection with canister filters. A discreet carbon dioxide diffuser provides a super fine and high rate diffusion safe for an aquatic tank.”
• Best for Artificial Plant Tank – PIVBY Aquarium CO2 Diffuser
  “Artificial plants can do well in almost any tank. However, the u-shaped design and inbuilt bubble counter are safe for a 20-gallon tank with any plant.”
• Best for DIY Tank – Yosoo DIY CO2 Diffuser
  “The high-quality design, coupled with the transparency of the glass makes the Yosoo gas spreader a good fit for a DIY tank setup with yeast, sugar, and soda bottles. It can be used in a large aquarium up to 80 gallons.”
• Best for 10 Gallon – Fluval Ceramic 88-g CO2 Diffuser
  “Originally designed to be used as a replacement diffuser part for the Fluval CO2 supply set, it can be used separately in a tank that holds up to 10 gallons.”
• Best Yagote – Yagote Stainless Steel CO2 Diffuser
  “The Yagote Stainless Steel C02 Diffuser is best for use in tanks with high light penetration. It is rustproof and easy to maintain. The delicate design and ease of use may not work well in a small aquarium.”
• Best Choice with Bubble Counter – Atman Enhanced Dissolution CO2 Diffuser
  “Need a diffuser with a sturdy bubble counter? This one from Atman fits the bill. With an integrated check valve, you can easily monitor changes in gas levels inside the aquarium.”
• Best for any Water – Pm0606 Micro Bubble CO2 Diffuser
  “The high-quality ceramic disc provides the right amount of bubble that is safe for any water. Whether for fresh or saltwater, you get a diffuser that is up to the task.”

My Reviews For The Best CO2 Diffusers in 2023

You will find below a detailed review of 15 of the best CO2 diffusers you can use in a fish tank. I have included the key features and pros and cons of each one of them. You will also find a buyer’s guide and frequently asked questions afterward.

1. Best Overall: JARDLI Pollen Glass CO2 Diffuser

My overall best pick is the JARDLI Pollen Glass CO2 Diffuser. It comes with a high-quality ceramic membrane that provides efficient CO2 atomization throughout the aquarium. The U-shaped design of the connecting tube prevents the blockage of gas flow, ensuring even circulation.

The 1.5-inch diameter of the device makes it suitable for use in a 30 to 50-gallon aquarium. Included in the package are two suction cups for a firm attachment. So you can ensure there will be an even flow of mist CO2 gas inside the tank. Overall you get a product that is highly durable, easy to use, and maintain.

Key Features:

• 2-suction cups
• U-shaped connecting tube
• High-quality glass bottle

Product Specifications:

Dimensions	1.5 inches
Weight	0.3 ounces
Gallon Capacity	20
Brand	JARDLI

2. Best Budget: S.T International Aquarium CO2 Diffuser

If you are in the market for a budget-friendly carbon dioxide diffuser, it is worth checking out this one from S.T International. It features high-quality glass materials that promote the distribution of CO2 in the form of tiny bubbles. The 0.8inch disc size makes it best for use in a small tank that holds 20 gallons of water.

Overall you get a decent diffuser that can hold up any day. It is also worth mentioning that it is one of the cheapest products out there. However, since it is made from glass, it is always best to take caution when cleaning the diffuser.

Key Features:

• 0.8-inch disc size
• Glass diffuser
• Narrow end tube

Product Specifications:

Dimensions	0.8 inches
Weight	0.32 ounces
Gallon Capacity	30
Brand	S.T. International

3. Best for Nano Tank: JARDLI Pollen Glass + Bubble Counter CO2 Diffuser

Finding a gas diffuser for a small aquarium could be quite the stress. However, you can save time if you are shopping for a 20-gallon tank or less by going for the JARDLI Pollen Glass CO2 Diffuser with bubble counter.

The glass tube is designed to be visually appealing, and the ceramic membrane allows for even gas spread in the tank. It comes equipped with a bubble counter so you can take control of the gas flow. Aside from being easy to use and maintain, you get a device that quickly attaches to the wall of your tank and gets to work.

Key Features:

• 0.8 Inch disc size
• Bubble counter
• Bright ceramic disc

Product Specifications:

Dimensions	0.8 inches
Weight	0.6 ounces
Gallon Capacity	20
Brand	JARDLI

4. Best for Large Aquarium: Fibst Aquarium CO2 Diffuser

The Fibst Aquarium CO2 Diffuser is worth checking out if you need a diffuser for a large-sized tank. It is designed to provide all-round bubbles as opposed to other brands that produce partial bubbles. It is made from stainless steel, which makes it equally durable and easy to maintain.

The kit is easy to install, and the ceramic sheet can be easily removed to clean the unit. In addition to getting a long-lasting product, you also get to enjoy a 6-months warranty for the ceramic layers and a 24 months’ warranty for other parts of the device. It can be used in an 80-gallon tank comfortably.

Key Features:

• Stainless steel diffuser
• Large-diameter disc
• Warranty included

Product Specifications:

Dimensions	13.8 x 2.8 x 1.4 inches
Weight	5.6 ounces
Warranty	6 months – 1 year
Gallon Capacity	100
Brand	Fibst

5. Best for 55 Gallon: Yagote Glass CO2 Diffuser

It can be quite challenging to find value these days, even when you have the money. Let’s face it shopping over the internet comes with a lot of worries. You have to worry about quality and efficiency. If this is what you are looking for in a CO2 diffuser, you may want to go for this one from Yagote.

It features a durable glass that is easy to install and use. It comes as a complete unit with a gas checker that helps monitor carbon dioxide levels in your aquarium. It is a versatile option that can work in a live and artificially planted tank. You could safely use it in a 55-gallon aquarium with ease.

Key Features:

• Glass diffuser
• Drop checker
• Suction cups

Product Specifications:

Dimensions	–
Weight	9.6 ounces
Warranty	30 days
Gallon Capacity	55
Brand	Yagote

6. Best JARDLI: JARDLI Music Glass CO2 Diffuser

If there ever were a CO2 diffuser that was worth gifting a friend, it would be the JARDLI Music Glass. Aside from being visually appealing, it is equally highly efficient in promoting the healthy growth of fish and plant matter inside an aquarium. The 2-inch diameter of the disc makes it best for use in a large-sized tank that holds up to 80 gallons.

The non-toxic nature of the glass material is safe for both fishes and live plants. Each glass is handcrafted and durable enough to hold up in any type of tank setup. Also, it is simple to set up and clean regularly. Although you to mind the glass, aside from that, you get a device that will meet your expectations.

Key Features:

• 2-inch diameter disc
• Suction cups
• Glass diffuser

Product Specifications:

Dimensions	2.6 x 2 x 6.3 inches
Weight	3.2 ounces
Gallon Capacity	75
Brand	JARDLI

7. Best for Fish Tanks: STARSIDE Aquarium CO2 Diffuser

If you house an amphibian like the Axolotl in your tank, the STARSIDE Aquarium CO2 Diffuser is a good option. It is made from durable glass with a high bending resistance and includes added gear like suction cups and a check valve. The resin glass is transparent and can work effectively without a bubble counter.

The u-shaped design of the tube, coupled with the short inch disc, makes it a good pick for a small tank. It is easy to maintain and can be used in any type of tank setup.

Key Features:

• U-shaped tube
• High bending resistance
• Glass diffuser

Product Specifications:

Dimensions	3.2 x 3.2 x 3.2 inches
Weight	0.6 ounces
Warranty	90 days
Gallon Capacity	60
Brand	STARSIDE

8. Best Versatile: Bluecell Aquarium CO2 Diffuser

The Bluecell Aquarium CO2 Diffuser is a highly versatile device that can work in any type of aquarium setup. It can be used in saltwater and freshwater tank and also works in a live or plastic planted tank. The packages include a bubble counter, a u-shaped glass tube, a check valve, and suction cups.

With a high bending resistance, the glass is long-lasting and can hold up in 30 to 50 gallons of water. It is simple to set up and clean at intervals.

Key Features:

• U-shaped tube
• Glass diffuser
• Suction cup

Product Specifications:

Dimensions	2.5 x 1.2 x 0.8 inches
Weight	0.8 ounces
Warranty	30 days
Gallon Capacity	50
Brand	Bluecell

9. Best In-line: NilocG Aquatics CO2 Diffuser

A planted fish tank will need a diffuser that provides a high rate and superfine gas diffusion. This is important to prevent the distortion of green matter inside the container. It also helps to keep all other water conditions such as pressure and temperature in check.

The NilocG Aquatics CO2 Diffuser features an in-line design that allows easy attachment to canister filters. The large diameter of the disc makes it best for use in a medium to large size tank. It is easy to install with options to attach directly or below the aquarium.

Key Features:

• Large size disc
• In-line canister mounts
• Composite diffuser

Product Specifications:

Dimensions	0.7 inches
Weight	3.4 ounces
Warranty	90 days
Gallon Capacity	70
Brand	NilocG

10. Best for Artificial Plant Tank: PIVBY Aquarium CO2 Diffuser

The crystal clear glass of the PIVBY diffuser has a high bending resistance and is capable of getting enough circulation in a plastic plant tank. The u-shaped design of the tube and the solved top make for the natural uptake of bubbles inside the aquarium. Thanks to an inbuilt bubble counter, improving plant and pet health can be done simultaneously.

The 0.78-inch diameter of the disc makes this one a good fit for 20-gallon tanks and below. The package includes a check valve and suction valve, which makes diffusion a lot easier.

Key Features:

• 0.78-inch disc
• Glass diffuser
• U-shaped design

Product Specifications:

Dimensions	0.7 inches
Weight	1.6 ounces
Gallon Capacity	20
Brand	PIVBY

11. Best for DIY Tank: Yosoo DIY CO2 Diffuser

If you use a DIY setup with yeast, plastic cans, and need a high transparent glass diffuser to create a sense of harmony in the system, you should consider this one from Yosoo. The high-quality glass is durable for use in medium to large-sized tanks that hold up to 100 gallons.

Included in the package are a check valve, bubble counter, and an ultra-micro atomizer. It is easy to install and operate and is easy to clean at intervals. Overall, you get a device that is highly efficient and can be easily configured to match any setup.

Key Features:

• Check valve
• Bubble counter
• Glass diffuser

Product Specifications:

Dimensions	1.58 x 0.98 x 1.58 inches
Weight	0.8 ounces
Warranty	90 days
Gallon Capacity	100
Brand	Yosoo

12. Best for 10 Gallon: Fluval Ceramic 88-g CO2 Diffuser

Fish tanks and aquariums require regular cleaning and supervision. This can take a toll on you, especially if you have a busy routine daily. It pays to get the best CO2 diffuser with easy maintenance to save you a great deal of stress. The Fluval Ceramic 88-g is one of the easiest to install and maintain.

The lightweight design and quick dispersal allow for even carbon dioxide circulation around the tank. It is safe to use around plastic and live plants and equally in any type of aquatic environment. The device is best for a small container that holds 30 gallons or less.

Key Features:

• Lightweight ceramic
• Simple design
• Composite diffuser

Product Specifications:

Dimensions	1.3 x 3.4 x 4.3 inches
Weight	0.6 ounces
Gallon Capacity	30
Brand	Fluval

13. Best Yagote: Yagote Stainless Steel CO2 Diffuser

The Yagote Stainless Steel CO2 Diffuser is a perfect fit for aquariums with high light penetration. If you have your tank sitting close to the window or an area of the house with high heat intensity, a stainless steel diffuser will be better than glass.

The elongated tube design provides high-quality diffusion through tiny atomic pores on the surface. The ceramic disc can quickly be detached for replacement or maintenance. The steel is resistant to rust and durable enough than glass options in the market. It is safe to use in any planted tank that holds up to 50 gallons of water.

Key Features:

• Stainless steel diffuser
• Elongated tube design
• Detachable ceramic disc

Product Specifications:

Dimensions	11.9 inches
Weight	8.8 ounces
Warranty	30 days
Gallon Capacity	50
Brand	Yagote

14. Best Choice with Bubble Counter: Atman Enhanced Dissolution CO2 Diffuser

A bubble counter helps you monitor the dispersal of CO2 in your aquarium. If you need a quality diffuser that features an inbuilt bubble counter, this one from Atman can get the job done. The integrated check valve makes it easy to monitor changes in the gas levels within the aquarium.

It can be attached to the glass of the aquarium or externally using the filter outlets. The suctions cups ensure that carbon dioxide is evenly pumped with each bubble. The large outer diameter makes it best for large tanks that hold up to 100 gallons of water.

Key Features:

• Large outer diameter
• Bubble counter
• Check valve
• Suction cups

Product Specifications:

Dimensions	0.8 inches
Weight	7.5 ounces
Gallon Capacity	100
Brand	Atman

15. Best for any Water: Pm0606 Micro Bubble CO2 Diffuser

The high-quality ceramic disc of the Pm0606 can hold up in both salt and freshwater conditions. The air stone built-in bubble counter ensures the CO2 bubble is smooth enough through the system. With even gas distribution, both plants and animals can thrive.

The durable construction and washable components are super long-lasting and easy to maintain. The micro diameter of the disc allows for quick attachment to small and medium tanks that hold up to 40 gallons of water.

Key Features:

• Airstone bubble counter
• Micro diffuser
• Efficient ceramic plate

Product Specifications:

Dimensions	1.0 inches
Weight	0.6 ounces
Gallon Capacity	40
Brand	Pmo606

Buying Guides

Now that I have shared with you 15 of the best aquarium diffusers available for sale, I can now discuss how to spot a winning product when shopping for a quality diffuser. You can learn more from the buyer’s guide below.

There are a few things you want to keep in mind when in the market for a gas diffuser for your fish tank.

Size Of Tank

The size of your tank is a lot important when looking to get a CO2 diffuser. In most cases, the outer diameter of the ceramic disc determines the surface area the gas can reach. Diameter sizes less than 1.5 inches can work for a 20-gallon tank or less. Large ones are best for medium to large-sized containers. You can check the review for my best picks for small and large aquariums.

Mode Of Installation

The way your tank is set up will determine how to install your diffuser. If you intend to have it inside the aquarium, you need to go for one that can easily be attached to the glass wall. Some options can be placed at the bottom of the tank, while others could be connected externally. You want to take note of this when looking to buy the best CO2 diffuser.

Long-Lasting

Even though they do not cost much, you should endeavor to consider the shelf life when shopping for an aquarium apparatus. While most of the products available are made from glass, some feature high-quality resin glass that is highly durable. However, if you want to avoid glass since it is fragile, it may be worth checking out those made from stainless steel.

Ease Of Maintenance

Maintenance is something you also want to consider when in the market for a CO2 diffuser. The ceramic disc will need to be cleaned at intervals or changed, so you should get a device that is easy to set up and clean. It is super easy to wipe glass clean, although you want to be careful not to break it in the process.

Added Gear

If you want your device to come with a check valve and bubble counter to monitor bubble count, you will need to go for a product that features added gear. Many of the products available are designed with a ceramic disc and glass housing, but there are equally others that feature a lot more. So you want to take note of this when in the market for a new CO2 diffuser.

Salt Or Freshwater

When shopping for aquarium accessories such as diffusers and regulators, you want to confirm that they are safe for your type of setup. Although most of the best CO2 diffusers made of glass can survive in a salt or freshwater environment, you want to make sure it is safe to use.

Frequently Asked Questions

I have provided answers to some of the frequently asked questions you may have when looking to buy a new CO2 diffuser for your fish tank below.

How can I install a CO2 diffuser?

Most are designed to be easily attached to the side of an aquarium wall or beneath the tank. Some others could also be fixed externally. It all depends on the way your aquarium is set up. It is always best that the bubble builds up from the bottom of the tank. This makes for even gas circulation throughout the system.

Do I need a bubble counter for a C02 diffuser?

If you are interested in counting the bubbles in your fish tank, you certainly need a bubble counter with your CO2 diffuser. Their main goal is to help tank owners identify how much carbon dioxide is circulated inside an aquarium. Keeping tabs on the amount of gas in the system is essential for marine life.

How do I clean a CO2 diffuser?

You will need to occasionally clean your CO2 diffuser every once a while. The procedure is simple and only requires to clean the diffusion membrane. For ceramics, a 1:1 preparation of chlorine and water solution should be enough to remove all debris from the diffuser. In-line diffuser could also make use of chlorine or bleach to clean the unit regularly.

Our Top Pick

A CO2 diffuser is highly essential in a planted aquarium. It plays a significant role in ensuring there is carbon dioxide in the system, which is needed for photosynthesis and the release of oxygen for marine life.

There are many options for tank owners to choose from. Just in case you missed it, my best pick out of the 15 CO2 diffusers in the review is the JARDLI Pollen Glass CO2 Diffuser.

You can also check the buyer’s guide to find some of the essential things to note when looking to buy one.