7 Best CO2 Diffusers for Aquarium Plants of 2020

Best CO2 Diffuser

Plants require CO2 to grow, after which they release oxygen back into the air. In planted tanks, the oxygen released back into the water causes the environment to be more unconducive for them to live in.

For this reason, it is necessary to increase the CO2 content in the water and this is where CO2 diffusers come in.

Diffusers operate like air stones, creating smaller bubbles of pressurized CO2, which increases the surface area for absorption into the water.

With that in mind, this article looks at the best CO2 diffusers that you should consider buying.

7 Best CO2 Diffusers – Reviews

IMAGE

​PRODUCT

​FEATURES

Pm0606 CO2 Bubble Diffuser

1. Pm0606 CO2 Bubble Diffuser (Our Pick for the Best CO2 Diffuser)

  • Supports plant and fish growth
  • Ceramic disc for bubble creation
  • Air control valve
Jardli JACOP40

2. Jardli JACOP40 (CO2 Diffuser with a Glass Tubing)

  • Glass housing and tubing
  • Ceramic disc
  • Available in 2 sizes
  • Included 2 suction cups
Jardli JACO02A

3. Jardli JACO02A (U-Shape Hanger-Style CO2 Diffuser)

  • Glass construction with a hanger-style top
  • 0.8-inch ceramic disc
  • Ideal for 20-gallon tanks or less
Fibst CO2 Diffuser

4. Fibst CO2 Diffuser (Stainless Steel CO2 Diffuser)

  • Strong stainless-steel construction
  • Ceramic disc for CO2 atomization
  • Available in 2 sizes
  • U-shaped hanger for easy installation
Yagote Glass CO2 Diffuser

5. Yagote Glass CO2 Diffuser (Best CO2 Diffuser for the Money)

  • Affordable
  • Unique intricate spiral glass design
  • Available in 3 sizes
Jardli JACOM50

6. Jardli JACOM50 (Best CO2 Diffuser for Big Tanks)

  • Large 2-inch diameter ceramic disc
  • Ideal for tanks exceeding 75 gallons in size
  • Comes with 2 suction cups
Atman Enhanced Dissolution CO2 Diffuser

7. Atman Enhanced Dissolution CO2 Diffuser (Most Efficient CO2 Diffuser)

  • Achieves 100% dissolution
  • Connects to the outlet of an external filter
  • Bubble counter and integrity check valve
  • Comes with 2 suction cups

PRODUCT

1. Pm0606 CO2 Bubble Diffuser

(Our Pick for the Best CO2 Diffuser)

Pm0606 CO2 Bubble Diffuser
  • Supports plant and fish growth
  • Ceramic disc for bubble creation
  • Air control valve

2. Jardli JACOP40

(CO2 Diffuser with a Glass Tubing)

Jardli JACOP40
  • Glass housing and tubing
  • Ceramic disc
  • Available in 2 sizes
  • Included 2 suction cups

3. Jardli JACO02A

(U-Shape Hanger-Style CO2 Diffuser)

Jardli JACO02A
  • Glass construction with a hanger-style top
  • 0.8-inch ceramic disc
  • Ideal for 20-gallon tanks or less

4. Fibst CO2 Diffuser

(Stainless Steel CO2 Diffuser)

Fibst CO2 Diffuser
  • Strong stainless-steel construction
  • Ceramic disc for CO2 atomization
  • Available in 2 sizes
  • U-shaped hanger for easy installation

5. Yagote Glass CO2 Diffuser

(Best CO2 Diffuser for the Money)

Yagote Glass CO2 Diffuser
  • Affordable
  • Unique intricate spiral glass design
  • Available in 3 sizes

6. Jardli JACOM50

(Best CO2 Diffuser for Big Tanks)

Jardli JACOM50
  • Large 2-inch diameter ceramic disc
  • Ideal for tanks exceeding 75 gallons in size
  • Comes with 2 suction cups

7. Atman Enhanced Dissolution CO2 Diffuser

(Most Efficient CO2 Diffuser)

Atman Enhanced Dissolution CO2 Diffuser
  • Achieves 100% dissolution
  • Connects to the outlet of an external filter
  • Bubble counter and integrity check valve
  • Comes with 2 suction cups

1. Pm0606 CO2 Bubble DiffuserOur Pick for the Best CO2 Diffuser

Pm0606 Micro Oxygen and CO2 Bubble Diffuser

Pm0606’s product is one of the best CO2 diffusers for aquariums because, apart from being supportive of plant growth, it is built with precision to create a conducive environment for shrimps, guppy, tetra and betta fish among many others.

The unit produces micro-fine bubbles, which increase surface area for contact with the water, leading to a very large absorption of CO2 gas. This is made possible by the use of a ceramic disc, which helps in releasing the gas in very tiny amounts, forming the fine bubbles.

An air control valve is included in the package and this helps in regulating the amount of CO2 that goes into the tank as well as the size of the bubbles being produced.

In terms of size, this product is available in a small, big, large and stick size, with the stick being very effective at creating a large number of bubbles on a wide, distributed surface.

However, this piece does not come with the required tubing and it requires regular cleaning, especially on the white ceramic.

However, this is a very simple task because of the small size and smooth surfaces of both the glass body and ceramic, which are easy to clean.

Pros:

  • Good for plants and fish
  • Creates micro-fine bubbles for maximum CO2 absorption
  • Air control valve for regulating CO2 release
  • Available in 3 sizes plus a stick model
  • Easy to clean

Cons:

  • Does not come with the required tubing

2. Jardli JACOP40CO2 Diffuser with a Glass Tubing

Jardli Pollen Glass CO2 Diffuser with U-Shape Connecting Tube

Jardli’s CO2 diffuser also features a ceramic disc that provides efficient CO2 atomization, and this is held in place by a glass housing and tubing. Though very fragile, the clear glass almost disappears in the water, creating the effect of a floating ceramic disc.  

For more effectiveness, this product is available in wide 1.5- and 2-inch diameter options, with the 1.5-inch option being suitable for 20 – 50-gallon tanks and the 2-inch option being suitable for 50 – 75-gallon aquariums.

These are wide enough for distributing the CO2 over a larger surface area for better absorption while the 2 included suction cups simplify installation to the tank wall.

On the downside, this diffuser does not have an airflow control feature. Instead, it has a very simple design that does not require adjustments every now and then.

Pros:

  • Ceramic disc for efficient atomization
  • Available in two sizes
  • Suitable for 20 – 75-gallon tanks
  • Easy to clean glass body

Cons:

  • No CO2 flow control valve
  • Glass construction makes it very fragile

3. Jardli JACO02AU-Shape Hanger-Style CO2 Diffuser

Jardli Glass CO2 Diffuser

Still from Jardli, this JACO02A is quite similar to the one above, featuring a glass construction in a U-shape design.

However, this has an extended glass tube that forms a U at the top for hanging it, which enhances its looks while also making it easy to install over the aquarium wall.

Although the unit does not come with the required rubber tubing for installation, the U hanger minimizes the length of tubing that is required since part of the glass hangs outside the aquarium, close to the gas tank.

A ceramic disc is included for CO2 atomization, but it is quite small as compared to the one in the pollen diffuser above. It measures only 0.8 inches in diameter and this makes it ideal for tanks that are less than 20 gallons in capacity (Nano tanks).

The small size, however, means that it is much easier to clean and requires less bleach water to do the job.

Pros:

  • Aesthetically beautiful U glass hanger
  • ​Easy to install
  • Easy to clean

Cons:

  • Does not come with the required tubing
  • Very small ceramic disc

4. Fibst CO2 DiffuserStainless Steel CO2 Diffuser

Fibst CO2 Diffuser for Aquarium

Fibst’s CO2 diffuser is quite unique because it is made of 304 stainless steel and not only does this make it strong and durable, but it also gives a mirror-like finish, which looks very elegant underwater.

Additionally, the unit has a similar U-shaped hanger like Jardli’s unit above, making it more aesthetically pleasing and easy to install.

The only problem though is that it has a small ceramic diffuser, measuring only 30 mm in diameter (slightly above 1 inch). A 20 mm option is also available and both sizes are ideal for use in Nano tanks.

Regardless of the size, the ceramic in each unit is safely secured inside a cup, which must be opened if you want to clean the disc. This ensures that no CO2 escapes without passing through the ceramic while also making it easy to clean since the disc is easily removable.

Pros:

  • Strong and durable stainless-steel construction
  • U-shaped hanger and a mirror-like finish give it a good look
  • Easy to maintain
  • Ceramic disc for CO2 diffusion
  • Available in 2 sizes

Cons:

  • Small ​diffusion surface area
  • No flow control valve

5. Yagote Glass CO2 DiffuserBest CO2 Diffuser for the Money

Yagote Glass CO2 Diffuser

If you are on a tight budget, Yagote’s CO2 diffuser is an affordable product to consider. Despite this, it has a very intricate design consisting of a spiral glass in a glass cup, which is very unique.

Additionally, this beautiful design is made using see-through glass, which blends very well with the water, creating a sense of harmony and unity with the tank.

A ceramic disc is installed above the cup for diffusing the gas and it contains atomic pores on its surface that release the gas in very small portions for maximum absorption.

However, this disc is very small in size, measuring only 3/4 inches in diameter, making it suitable for 15 – 50-gallon planted tanks.

If you have a bigger aquarium, there is a 1.6-inch diameter option that is suitable for 30 – 50-gallon tanks and a 2-inch option that is suitable for 50 – 75-gallon aquariums. With these options, you will certainly get a perfect match for your tank.

You also get a suction cup for fixing the diffuser on the aquarium wall and all you have to do is attach tubing to connect it to the pressurized CO2 canister.

Pros:

  • Affordable
  • Beautiful spiral design
  • Ceramic disc diffuser
  • Available in 3 sizes
  • Easy to install

Cons:

  • Fragile glass construction.

6. Jardli JACOM50Best CO2 Diffuser for Big Tanks

Jardli Music Glass CO2 Diffuser

Jardli’s music glass CO2 diffuser is quite expensive but this is because it has a 2-inch diameter ceramic disc that is designed for larger tanks with capacities of 75 gallons and above.

In terms of design, the unit closely resembles a small coffee cup with a glass tube rising high above it. Even though the required rubber tubing is not included, this glass tube is standard sized to connect with 2/3 mm tubing. However, it comes with 2 suction cups for easy installation.

An important thing that you need to note is that the whole diffuser should be soaked in water for at least 30 minutes before use and the glass tube should be inserted in water before connecting it to the rubber tubing. This will prevent any damages to the glassware.

Pros:

  • 2-inch diameter disc for use in large tanks
  • Ceramic disc for efficient atomization of CO2 gas
  • Comes with 2 suction cups for easy installation

Cons:

  • Does not come with the required tubing
  • Expensive

7. Atman Enhanced Dissolution CO2 DiffuserMost Efficient CO2 Diffuser

Atman Enhanced Dissolution CO2 Diffuser

Atman’s unit is the top-rated CO2 diffuser in this list and this is because it achieves a 100% dissolution in water, making it super-efficient.

To achieve this, the diffuser is designed quite differently as compared to the other units above. Instead of being placed inside the tank, it is connected to the outlet from an external filter, from which it carbonizes the water with no CO2 loss.

A ceramic cylinder is used to create the bubbles, with the water passing inside while CO2 is forced into the water from outside the cylinder. This cylinder is enclosed inside the diffuser’s main body and this ensures that there is no gas lost, which is very efficient.

The only problem with this system is that the ceramic requires to be replaced every 6 – 8 months, which is an expensive option as compared to the cleaning required in the other models.

Other features include a bubble counter, an integrity check valve and 2 suction cups for easy installation on the tank wall.

Pros:

  • Achieves a 100% dissolution in water.
  • Ceramic cylinder diffuser
  • Features a bubble counter
  • Comes with 2 suction cups for easy installation

Cons:

  • Requires a functioning filter in order to work
  • Ceramic requires replacement instead of cleaning

How to Buy the Best CO2 Diffuser

How to Buy the Best CO2 Diffuser

1. Compatibility

Before buying a CO2 diffuser, you should check its compatibility in terms of the tank size that it can handle.

This is usually determined by the size of the ceramic disc. The smaller the disc, the smaller the surface area for releasing CO2 bubbles and thus, the smaller the tank that it can handle.

Most units with ceramic discs that are 2 inches or larger ​such as Jardli's JACOM50 are ideal for large tanks of over 70 gallons, but this is just a rough guide. Ensure that you always check a diffuser’s tank capacity rating before buying so that you do not over or under saturate your tank with CO2.

2. Material

CO2 diffusers are usually made from either glass or stainless steel. While glass blends very well with the tank water, it is very fragile and thus, such CO2 diffusers must be treated with care.

Stainless steel, on the other hand, makes the diffusers have a mirror-like appearance underwater, which is still a good finish. The biggest advantage with this construction though is that it is very strong, which means it does break easily and does not require delicate handling.

If you are a clumsy person, you better go for ​Fibst's CO2 Diffuser. However, if you can handle glass carefully, a glass ​diffuser ​such as Jardli's JACOP40 will do. 

3. Ease of use

A diffuser’s ease of use is mostly considered in terms of how easy it is to clean.

Diffusers with ceramic discs are very easy to clean because you only need to use a bleaching agent to remove the discoloration, then rinse it thoroughly.

However, some products such as Atman Enhanced Dissolution CO2 Diffuser require the ceramic to be replaced ​every 6-8 months and this makes it easier to maintain since a replacement means that no cleaning is required.

On the downside, these replacements are expensive. 

4. Accessories

Accessories are also a big thing to consider because they save you the cost that you would otherwise incur in buying the items.

In terms of CO2 diffusers, the accessories to look for in the package include an air flow control valve, which regulates the amount of CO2 that goes into the diffuser cup and ceramic disc. With this, you get to have more control over the rate of release of the gas into the tank.

Suction cups are also an important thing to consider because they are used in the installation process by helping you stick the unit to the aquarium wall.

Although most diffusers do not come with their required rubber tubing, this is still a very valuable addition and thus, if you get a diffuser that comes with its tubing and at a good price, the better.

Best Place to Put the CO2 Diffuser 

There are a few things to consider before deciding on where to place the CO2 diffuser in the tank. First of all, if it is an inline unit such as Atman’s diffuser in the review above, there’s no debate about it. It should be placed on the return lines from an external filter.

For the in-tank unit though, the best place to install it is close to the bottom of the tank. At this depth, bubbles will take a longer time to reach the surface and thus, more CO2 will be absorbed.

To make the bubbles spend more time in the water, the position that you select should be under the return lines of the filter. This way, the water will push the bubbles back into the water for more CO2 absorption.

An important thing to note is that you should not place the unit under the substrate or among the plants. The idea here is to let the bubbles flow freely without any interference.

If they encounter the substrate or plant leaves, they might combine to form larger bubbles, which reduces the surface area for the gas to dissolve and thus, a lot of CO2 will go to waste.

Conclusion

Whether you have a freshwater or a saltwater planted tank, you will most likely need additional CO2 to help the plants grow stronger and healthier.

The products described above are the best CO2 diffusers that can help you with this and ​we recommend Pm0606’s ​diffuser as the top one to consider buying. 

Read More: 7 Best UV Sterilizer Aquariums


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