5 Best CO2 Diffusers [2019]

It’s common knowledge that carbon dioxide (CO2) is essential when it comes to promoting healthy and vibrant plant growth in all areas of life, regardless of where you are on the planet. This, of course, includes your aquariums and fish tanks.

There’s no denying the atmosphere of a tank and the health of the life living inside it will depend on the plant life also inside, which is why it’s so important to give your plants everything they need; in the case of CO2, this comes through a diffuser.

This is a piece of equipment used to manage and control the amount of carbon dioxide flowing into your tank. With the right levels of carbon dioxide in your tank, you’ll find your plant life thrives and then allowing your tank to benefit from all the benefits that come with it, such as increased oxygen production, happier fish and organisms and the right level of nutrients in the water.

However, while the benefits are undeniable clear, the first thing you need to do is to find the diffuser that’s best for you. You’re going to need one that provides the right amount of carbon dioxide to your tank as well as being able to handle the size of your tank.

You’ve come to the right place.

Today, we’re going to explore the five best CO2 diffusers out there for aquarium fish tanks. We’re going to explore all the basics and different types out there, as well as exploring each one in detail, so you have everything you need to make the best decision for you.

Let’s jump straight into it!

Glass Inline CO2 Atomizer Diffuser for Aquarium Planted Tanks

Glass Inline CO2 Atomizer Diffuser for Aquarium Planted Tanks

To start off our list, we’ve chosen the Glass Inline Diffuser for a number of reasons. Firstly, and perhaps most importantly, this is a really affordable model that’s suitable for budget buyers and experienced tank owners who are prepared to spend above the average asking price.

Secondly, since this is an atomizer diffuser – a modern type of diffuser that makes adding carbon dioxide to your tank more effective – your tank will be able to enjoy a fine mist of CO2, rather than disruptive bubbles.

Not only does this make your tank look a lot more attractive, rather than just big bubbles, it also helps to distribute the CO2 evenly around the tank using the natural flow of the water. Thirdly, thanks to the inline design, there’s a reduced risk of algae growing on the diffuser; a common problem since the area tends to be CO2-rich.

Installation of this diffuser is really simple and all the instructions you need to know come with your order, so there’s no guesswork or trying to figure out how it works. Simply plug the diffuser into your canister filter and add a canister of pressurized CO2 and you’ll be good to go!

  • Really simple to install and setup
  • An affordable diffuser solution
  • Designed to prevent algae growing on the side of the device
  • Diffuses CO2 as a fine mist for effective distribution
  • A little noisy while in operation

Pollen Glass CO2 Diffuser with U-Shape Connecting Tube for Aquarium Planted Tank

Pollen Glass CO2 Diffuser with U-Shape Connecting Tube for Aquarium Planted Tank

If you’re looking for a diffuser that’s a little more traditional, but still gets the job done and adds a nice aesthetic feature to your aquarium, the Pollen Glass diffuser should definitely be at the top of your list of considerations.

This diffuser is connected to your fish tank using a universal U-shape connecting tube which makes it easy to install. The device is then placed at the bottom of your tank wherever you want it to go. There’s no need to worry about sticking or attaching it to the sides of your tank. Once placed, you’re good to go!

This particular model is designed with a 1.5-inch diffuser head which makes it ideal for aquariums between 30-50 gallons in size, which ideal for the most average tanks out there. What’s more, this is also one of the most affordable diffusers available today!

In short, this is one of the best diffusers available, and there’s really nothing bad to say about it. The vast majority of past customers are completely happy, and it really does everything it’s supposed to in the best possible way. Are you looking for a reliable and trustworthy diffuser? Here it is.

  • One of the most affordable diffusers available
  • Plug in, position and you’re good to go
  • Ideal for 30-50-gallon tanks
  • Produces small bubbles that look great
  • Not suitable for larger tanks

NilocG Aquatics Intense Atomic Inline CO2 Atomizer Diffuser for Planted Aquarium Tanks

NilocG Aquatics Intense Atomic Inline CO2 Atomizer Diffuser for Planted Aquarium Tanks

Next up, we’ve opted for the NilocG Aquatics Atomizer Diffuser, a small yet effective device that’s designed to make introducing CO2 to your aquarium as easily as possible, as well as producing the best results.

This little unit is incredibly discreet and connects inline to the air flow pipes you’ll already be using in such a fine way that it allows for 100% dissolution with the water in your tank. There’s no big bubbles and no chance of some areas being covered, and others not.

All in all, this is another diffuser that does exactly what it’s supposed to and aims to give you the best experience. This is one of the most consistently highly rated diffusers with hundreds of past customers stating how it’s done exactly what it’s supposed to do.

Installation of the device is simple and easy, and there’s a variety of positions you can set it up in to make it as easy as possible for you. Everything you need to get set up and running, including instructions, are all included with your purchases, and there’s no need for guesswork.

The device is really well made and durable, although it’s made from plastic rather than the industry standard of glass, there are no reports of it breaking easily or leaking. This ensures you have a reliable diffuser you don’t have to worry about breaking or being a waste of money.

  • A durable and reliable diffuser
  • No-leak design confirmed by hundreds of past customers
  • Easy to set up and install with instructions
  • An affordable diffuser solution
  • None!

Music Glass CO2 Diffuser for Aquarium Planted Tank (beyond 75-Gallons)

Music Glass CO2 Diffuser for Aquarium Planted Tank (beyond 75-Gallons)

While all the diffusers we’ve listed already are ideal for smaller, more average sized aquarium planted tanks, many of them aren’t really suitable for larger tanks. If you’re living with a tank that sits over the 75-gallon mark, don’t worry; this is the diffuser for you.

The Music Glass diffuser is designed with a 2-inch diameter which is much larger than some of the other diffusers here, but it continues to produce still microbubbles that evenly distribute CO2 into the water of your tank, mixing it with the natural water flow.

What’s more, the unique U-Bend design, which is designed to minimize the risk of blockages completely, looks amazing regarding the design of the product itself and the aesthetically pleasing bubble output which creates a nice amount of depth into your tank.

We also love this diffuser is so easy to set up in no time at all. The unit comes with two suction cups you simply connect to the airflow pipe and then stick to the side of your tank. It’s that simple.

Overall, this is another highly rated diffuser that really has nothing bad to say about it. Some claim the design is a little brittle, but by making sure you’re careful, you have nothing at all to worry about.

  • Suitable for aquarium tanks over 75-gallons
  • Easily set up using 2x included suction cups
  • Bubbles dissolve really nicely into the tank
  • A super-affordable device
  • Some customers state the design is a little brittle and requires care

Atman Enhanced Dissolution CO2 Diffuser w Bubble Counter & Check Valve for Aquarium Planted Tank

Atman Enhanced Dissolution CO2 Diffuser w/ Bubble Counter & Check Valve for Aquarium Planted Tank

The final diffuser we’ve chosen for planted aquarium tanks comes from Atman. This is another mid-range diffuser that ticks all the boxes in terms of performance and price. If you’re looking for a great little diffuser that helps to optimize the plant life of your tank, it doesn’t get much better than this.

As the title suggests, this is an enhanced dissolution CO2 diffuser. This means the unit uses high molecular PE ceramics to help diffuse the CO2 in the most effective and most evenly distributed way. This might sound complicated but, in short, it means you get some of the best results.

However, one of the best-selling points of this unit is the fact it comes with both a bubble counter and a check valve. These are both used to help you control exactly how much CO2 you’re allowing into your tank and confirming how it’s to be distributed; ensuring you have full control.

Suitable for both seawater and freshwater fish tanks, this is another one of the most highly rated diffusers enjoyed by people all over the world. Just make sure you’re following the included instructions to ensure you’re setting it up right!

  • A powerful diffuser complete with a bubble counter and check valve
  • Distributes CO2 evenly and effectively around your aquarium
  • Clean and clear CO2 flow around your pipes
  • Can be a little complex to set up compared to other units, but does contain instructions


While adding the right amount of CO2 into your fish tank can sound like an overwhelming and confusing process, as well as trying to maintain the right levels over long periods of time, it’s easy to see there are many devices out there that can help have the best experience.

Leave a Reply

Notify of