The Best Co2 Diffusers for Aquarium in 2021


If you want to keep the great health of the plants in your tank, you should be looking for the best CO2 diffusers for aquarium. It can offer you with plenty of benefits including helping maintain the health of your plants.

You can also rely on this item for keeping the fishes in the tank healthy, too. As if you keep the plants on top of their health, it can benefit your fish because such product can also help in maintaining the balance of CO2 in the water, too.

Definitely, such product is essential to have in your tank, but then selecting one can be difficult if it’s your first time buying it. For help, you can check out our buying guide that features the top picks in the category. You can also compare your options better with the things to consider as outlined in the following sections. If you’re ready, let’s start with the top six picks in the category below.

What is the Best CO2 Diffuser for Aquarium in 2021

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Top 6 Best Co2 Diffusers for Aquarium Reviews

1. JARDLI CO2 Diffuser with Bubble Counter


The JARDLI diffuser is known for its beautiful aesthetics. Due to its clear design, it can easily blend well into your aquarium’s surroundings.

Not only have that, this CO2 diffuser is made out of high-quality glass materials. With this, you are assured that your product is durable and will last a long time.

The JARDLI CO2 diffuser also provides a reliable and steady performance. Due to its bowl shape, this CO2 diffuser can dissolve up to 98% CO2. Its ceramic membrane even ensures the atomization of CO2 in large surface areas. As a result, you get healthier and livelier aquatic plants.

Moreover, the JARDLI diffuser also comes with a built-bubble counter that further optimizes its performance.

The JARDLI pollen glass CO2 diffuser measures 0.8 inches. As such, it’s recommended for tanks with capacities under 20 gallons.


  • Ceramic membrane
  • Built-in bubble counter
  • Visually-appealing
  • Reliable performance
  • For small tanks


  • Easily accumulates dirt and algae

2. JARDLI Pollen Glass CO2 Diffuser with Connecting Tube


JARDLI is known for its sophisticated and stylish products. Their U-shaped CO2 diffuser is not an exception.

This CO2 diffuser comes in a U-shaped bowl that gives it a stylish and elegant appearance. It’s made out of high-quality clear glass, allowing it to blend into your tank easily. With this, you get to enhance your aquarium tank’s visual look.

Not only that, the JARDLI CO2 diffuser is known for its top-notch CO2 dispersion. It can dissolve up to 98% of CO2 as well as evenly distribute it inside the tank. As a result, your aquatic plants will grow healthier and stronger.

The JARDLI CO2 diffuser can only be sued for tanks with a capacity ranging from 50 gallons to 75 gallons. As such, it’s a perfect choice for those with smaller tanks.

This CO2 diffuser also comes with its own tubing and 2 suction cups.


  • For small tanks
  • Even CO2 dispersion
  • Stylish appearance
  • Ceramic membrane
  • Durable


  • Might not fit to other standard tubes

3. Rhinox Nano CO2 Diffuser


The Rhinox Nano CO2 diffuser is known for its slow and controlled release of CO2 into your aquarium tank. Boasting high-quality features, this remains a favorite among tank owners.

In terms of design, the Rhinox CO2 diffuser features a blend of style and efficacy. Made out of high-quality glass, this CO2 diffuser is visually pleasing and is unobtrusive.

Moreover, its cylindrical shape and its small porous ceramic micro bubble diffuser plate give you a bigger but controlled CO2 diffusion. The cylindrical shape slows down the water speed while the bubble diffuser plate increases the surface area.

The CO2 diffuser is also easy to install and use since it comes with installation accessories. It’s also not difficult to operate.

The Nano CO2 diffuser is suitable for tanks with a capacity of 20 gallons.


  • Controlled CO2 diffusion
  • Unobtrusive design
  • Durable construction
  • Easy to install and operate
  • Affect a large surface area


  • Noisy

4. STARSIDE CO2 Regulator & U Shape CO2 Diffuser


Made out of high-quality materials and boasting numerous features, the STARTSIDE CO2 diffuser is well known among tank owners.

The STARSIDE CO2 diffuser comes in a U-shaped style, and it is made of high-quality resin material. Moreover, the product is equipped with a high-bending resistance feature, assuring you of its durability.

Aside from that, it provides a reliable and solid performance. Its ceramic disk is connected to its glass. This setup allows the system to generate a light stream of bubbles. Moreover, with its design, you can even an even CO2 diffusion and distribution.

The STARSIDE CO2 diffuser is also easy to install. This kit includes a suction cup and a check valve. Moreover, the U-bend is a separate piece that you can detach and adjust if necessary. With this, you can easily move it to adapt to your tank’s features.


  • High-binding resistance feature
  • Unobtrusive design
  • Easy to install and use
  • Resin construction
  • Even CO2 diffusion


  • Difficult to clean ceramic disk

5. JARDLI Music Glass CO2 Diffuser for Aquarium Plant


Like all of its products, JARDLI provides elegance and efficacy in one design. As such, it remains a favorite for many tank owners.

The JARDLI music glass CO2 diffuser boasts a large and even CO2 diffusion. Its high-quality ceramic membrane is embedded with nano holes intended to disperse the CO2 bubbles in a fine mist. As such, they can easily break down up to 98% of CO2 in your tank.

Moreover, its U-shaped tube also enhances its performance. With its width, it can disperse CO2 in a wider area and aid in the absorption process. The design is also meant to prevent CO2 blockage in your tank.

In terms of design and durability, this CO2 diffuser is superb. Made out of high-quality borosilicate glass, the product is durable and safe to use for your tank. Its design also makes it more visually appealing while remaining unobtrusive.


  • Aesthetically pleasing
  • Safe to use
  • Even CO2 diffusion
  • High-quality
  • Ceramic membrane


  • Easily gets clogged with algae

6. Fibst CO2 Diffuser for Aquarium


Made out of stainless steel, the fibst CO2 diffuser boasts high quality and durability. Not only that, this material gives it a sleek, mirror-like finish. As such, this gives it quite an elegant and stylish look underwater. However, despite its elegance, it still remains unobtrusive.

With a U-shaped hanger and ceramic disc, it provides a solid and reliable performance. With these components, the fibst CO2 diffuser boasts an even CO2 dispersion and diffusion. Moreover, the disc is stored inside a cup, ensuring that CO2 bubbles will not escape.

This product is also easy to install and clean as it has detachable parts. It also comes in 2 sizes, making it quite versatile. The fibst CO2 diffuser also offers a 6-month warranty for the ceramic sheet and a 24-month warranty for its other parts.


  • Elegant and unobtrusive design
  • Stainless steel construction
  • Easy to install and maintain
  • Comes in 2 sizes
  • Even CO2 diffusion


  • Small CO2 diffusion

Co2 Diffuser for Aquarium Buying Guide

A CO2 Diffuser is an important device if you are planning to establish a whole CO2 regulation system in your aquarium. The lives of the marine species in the tank matters, hence, it is advisable to be thorough in selecting the best CO2 diffuser. Here are the aspects that must be checked when buying a CO2 Diffuser for aquarium.

Size of the Aquarium

Before you start looking for a CO2 Diffuser, know what you need first by determining the size of the aquarium where you are going to use the diffuser. There are flexible CO2 diffusers that can be installed either in a small or large tanks. The downside is this type may just cost higher. Why spend for such types if you can already have a cheaper diffuser that can already do the work, especially for smaller tanks.


CO2 diffusers come in different types, sizes and construction materials. Most often, this is also the basis of their prices. Like for example, if you are planning to get a versatile CO2 diffuser, you might want to pick a brand that sells a CO2 Reactor. This is known to be the most expensive type. On the other hand, if you are tight on budget yet aims for a competitive quality, a glass or ceramic diffuser will already go a long way.


Keeping the whole aquarium and all the species in it takes a bit of effort so you might want to get a CO2 diffuser that will not be a burden in maintenance. Like the mere tank, CO2 diffusers also need regular cleaning. For this reason, you may choose a diffuser that is made of glass and those with forms like cylinder, disk and U-shape. These are known to be the easiest to tidy-up.


One of the major factors to check when searching for a good quality of CO2 diffuser is the way it is constructed and what materials it is made of. It matters because it is the basis of the resilience of the device and the length of time it can last.

Among the CO2 diffusers, many tank owners trust those items that are made of either glass, ceramic and stainless steel.

Accessories and Warranty

Majority of CO2 diffusers may cost lesser than the other components to run a healthy environment inside the tank. However, it is still wiser to patronize those brands or stores that offer a good warranty deal and with freebies. Other accessories that usually incorporated when you buy a CO2 diffuser are tubing and suction cup.

What is a Co2 Diffuser for Aquarium?


A CO2 Diffuser is a significant part of a CO2 regulation system along with a regulator, bubble counter, tubing and CO2 bottle or cylinder. The main function of a CO2 diffuser is to receive big bubbles from the counter and minimize their sizes. Once the Carbon Dioxide turn smaller in size, the plants feed from it for nourishment and for execution of photosynthesis with some help of lights.

Types of Co2 Diffusers

There are different types of CO2 diffusers that come in the same function but vary in features, sizes, construction and prices. Some of the most popular diffusers are as follows.

Ceramic Glass Co2 Diffuser – It is one of the most famous CO2 diffuser especially for smaller aquariums. This may cost lesser than the other types yet it exhibit a great performance in creating tiny CO2 for the benefit of marine plants.

In Line Diffusers – This type of CO2 diffuser is ideal for bigger tanks. It is also called as invisible CO2 diffuser because it is barely seen once it is installed. The advantage of In-line diffuser is its wide compatibility among hose diameters and silent performance.

Ladder CO2 Diffuser – It is called by its name because it literally looks like a mini ladder. It is also best for tanks with average size. However, its price tag is higher than the ceramic diffusers.

Airstone Diffuser – Among all the types of aquarium CO2 diffusers, this one is the least favored by many tank owners. In aquascaping, what is needed is a diffuser that can burst CO2 into micro sizes. However, an Airstone Diffuser does the opposite.

CO2 Reactor Diffuser – This one is the most suitable type of diffusers for people who own huge aquariums and those who breed fishes in tanks. Though it comes in a whopping high price, it can serve the users really well. It is efficient in producing microscopic CO2 bubbles and does not leak at all.

Why Do You need Co2 Diffuser for Aquarium?

A CO2 diffuser is an essential component in aquascaping. If you are a responsible pet owner, you can’t miss putting an efficient CO2 regulation system under your tank. And a CO2 diffuser is part of the said system. Here are the reasons why it matters.

CO2 diffusers help in increasing the Carbon Dioxide Diffusion. As the CO2 diffuser boosts plenty of tiny bubbles, this improves the balance in the ecosystem under the tank as well as the exchange of oxygen and carbon dioxide among the living creatures in it.

CO2 diffusers aid the health of marine plants. To make a more realistic aqua environment in aquariums, various species of plants are plotted on the tank’s bed. If ever you see Java Moss, Water Wisteria and Anubias looks a bit pale, this might be caused by carbon dioxide deficiency. That is where the role of the CO2 diffuser comes-in. It ensures that the plants receive the right quantity of Carbon Dioxide that they need to live happily and healthy.

CO2 diffusers keep the fishes and other creatures in the tanks alive and kicking. As earlier mentioned, the CO2 diffuser makes the plants healthy and these things are healthy, who benefited the most are the fishes. They tend to receive additional nutrients and enjoy roaming around the healthy marine bushes. Aside from that the CO2 diffusers helps in facilitating the balance of carbon dioxide in the water that is released by the fishes.

CO2 diffusers prevents Algae invasion – Massive spread of Carbon Dioxide triggers the growth of Algae. Once Algae dominates the place, it causes a bad environment for the fishes that may sicken or worst kill them. Hence, CO2 diffusers moderate the said gas inside the tanks to avoid algae existence.

Frequently Asked Questions


How to clean co2 diffuser?

Majority of the CO2 diffusers are meant for less maintenance. Few problems encountered though are discoloration while other diffusers tend to gain Algae and some types of dirt or substrate after a long time of use.

The best way to clean them is to uninstall them first. It is ideal if you have a spare so the process inside the tank won’t be affected. What you need to tidy it up is usually seen in your cleaning cabinet, which is the chlorine bleach. Soak the CO2 diffuser in a water solution with bleach. Let it submerged in it for at least 24 hours to remove the stain and dirt. You may do it once or twice a month or as the need arises.

Where to place co2 diffuser?

A CO2 Diffuser can be installed in any space inside the tank as long as you make sure that it is the best place where blockage won’t occur. Ideally, it should be positioned near the bed of the aquarium. Some also put it close to the water filter since bubble circulation is immense here.

Usually, the CO2 diffuser is connected on the bubble counter. After it is fully assembled, it is ready to be submerged in the tank.

Where to buy co2 diffuser for aquarium?

Every aquascaping requires a good CO2 regulation mechanism to breathe life for the plants and fishes inside the tank. Hence, searching for its components like the CO2 diffuser is not really a problem because there is a lot of market for it.

If you are a beginner in fish keeping hobby, you can easily find a CO2 diffuser in just one click. Only go to online shops like that already built their reputation in selling different items so you can also avoid fraud.

Here you can save time and effort since you can already compare the prices, features and quality of the products from different brands base on their specifications. Once you click the “add to cart and check-out”, you may just have to pay for the shipping fee though.

Meanwhile, if you are too meticulous that it requires you to touch and scrutinize the CO2 Diffuser first before purchasing, then you can also go personally on stores. Commonly, some pet shops already sell accessories like it.


Before buying the best CO2 diffuser for aquarium, it pays off to determine the most essential things to consider like your tank’s size, maintenance, cost, construction, accessories and warranty. All these things will help you figure out which among those choices are the most reliable ones in the category.

For further help, you can also select one among the top picks that meet the high standards of tank owners in the world. Each of these items is with pros, cons and special qualities that separate them from one another. Definitely, your tank will not be complete without a carbon dioxide diffuser. Make an informed decision by choosing among the best products in this category today!

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