7 Best CO2 Diffusers for Aquarium 2019

best co2 diffuserThe health and life of every creature in the home aquarium matter to any dedicated aquarium hobbyist a great deal and this is one of the reasons it is important to invest in the right set of devices. One of such devices is the CO2 diffuser which I seek to shed some light on in this article.

Why do i need a CO2 diffuser in my home aquarium, you may ask? Well, to address this question, it is expedient that we look at the (positive) impact of CO2 in the aquarium space. CO2 is a basic requirement for plant’s sustenance,  and with plants being needful for the growth, development and breeding of many aquarium fish species, having a CO2 diffuser incorporated into the tank set-up is a sine qua non.

What is a CO2 diffuser?

A CO2 diffuser is a device that functions to dissolve the CO2 gas emanating from the CO2 cylinder by breaking down big bubbles into small/tiny bubbles which, in turn, enhances the distribution of CO2.  CO2 diffuser specifically supplies carbon dioxide to the plants in the tank, and also regulates the amount of the gas available therein. The CO2 diffuser is one of the 3 major devices that are required to make up an effective CO2 regulation set-up – the other two devices being the CO2 cylinder and CO2 regulator.

With the generation of the tiny bubbles – through the action of the CO2 diffuser – more CO2 gas is absorbed by the water for the plants to take up and utilize during photosynthesis. The availability of CO2 in the aquarium will, in no small measure, help in limiting or preventing the growth of algae therein. It then follows that the CO2 diffuser should be seen as an integral part of any planted tank that is to be deemed fit for harbouring aquatic pets.

Looking into the market, you will come across a variety of this particular device that have been made to ensure optimal supply of the gas. And, it is with this in mind that I have found it of necessity to share products in the market today and also discuss how you can operate the device.

Discover more about seven of the best CO2 ­diffuser out here.

1.Yagote CO2 Diffuser:

This is a high-performing CO2 diffuser that will not only supply the adequate CO2 required for providing nourishment for your plants [with nutrients] but ensure their health is boosted on the whole. The design and quality that this piece portrays is simply top-notch and these are just some of the reasons this very CO2 diffuser ranks among the very best.

The Yagote CO2 diffuser features a ceramic disc which is highly efficient in helping to create bubbles needed to enhance the distribution of the gas (i.e. CO2) across the aquarium. Another interesting aspect of the Yagote CO2 diffuser is its cylindrical shape which plays a tremendous role in dissolving the gas for it to be proportionately distributed. Besides all these, it also comes with other relevant features that make it to function optimally and even easy to set up. By the way; it is fitting for a tank with a capacity of 60-200 litres. The compactness of the Yagote CO2 diffuser is one of the many reasons aquarists have come to love it. Furthermore, that it can easily blend with the aquarium space is seen as a plus. And, of course, different persons that have used it at one point in time have had something positive to say about its functionality and ease of installation. The Yagote CO2 diffuser does appear to be a reasonable choice for anyone on a low budget for CO2 diffuser.


  • Compact
  • Transparent
  • Easy to install
  • Affordable


  • Ceramic disc is not large enough
  • Suction cup may not always hold forth

2. RhinoxSpio III CO2 diffuser:

If you are about a CO2 diffuser that you can easily integrate into your pressurized tank set-up without any worry over functionality and ease of installation, then this piece from Rhinox should be what you are looking for. Made from top quality glass, this particular CO2 diffuser does its job [of making CO2 spread within the aquarium] in an expedient manner. Some of the features that make the RhinoxSpio III CO2 diffuser highly effective include the spiral tubing – which ensures the slow movement of the CO2 gas to achieve good dissolution – and the ceramic disc with pores that help make the CO2 available in form of bubbles across the aquarium – to be utilized by the plants therein.

This CO2 diffuser can be used in a tank with a maximum of 75 litres. Also included in the package are suction cups to ensure ease of installation.

One overarching theme that plays out over and again from customer reviews concerning the RhinoxSpio III CO2 diffuser borders on its effectiveness as customers are seen speaking highly about how well it has functioned, particularly when it boils down to dissolving and diffusing CO2. Apart from this, a few customers have also had positive reviews to contribute with respect to some features [like ceramic disc, and glass reactor].


  • Highly efficient ceramic disc
  • Intricately designed
  • Easy to use and set up.


  • Could generate noise when in use in some instances.

3. JARDLI Pollen Glass CO2 Diffuser:

This is another good option of a CO2 diffuser to use in the home aquarium when you are looking to boost the growth and development of the plants therein. The major part of this CO2 diffuser has a unique bowl-like structure unto which a ceramic membrane – which is largely responsible for the dissolution of a considerable amount of CO2 is affixed.

The JARDLI Pollen Glass CO2 diffuser also features a U-shape tube which is very useful in ensuring the unhindered distribution of CO2 in the tank. Additionally, it comes with suction cups which will be needful for the purpose of installation. This CO2 diffuser is suitable for pressurized tanks having a capacity of between 112 – 190 liters.

Aquarists that have used the JARDLI Pollen Glass CO2 diffuser have frequently expressed great satisfaction with the way it has been  functioning especially as it regards the rate at which it produces bubbles, as well as the fineness of the bubbles. Another area that has got customers speaking highly of the JARDLI CO2 diffuser is simple design that does not allow it to be eyesore or dent the beautiful appearance of the tank; rather it complements the aesthetic appearance of the tank. And, it is based on this that an ample of customers would readily recommend this piece to other aquarists.


  • Highly efficient
  • Adds aesthetic value to the tank
  • Does not need much tubing
  • Produces relatively minute bubbles

CONS: Somewhat fragile

4. NilocG Aquatics CO2 Diffuser:

Technology, no doubt, makes a difference in our world and this is also well reflected in the NilocG Aquatics CO2 diffuser made of unquestionable quality and with tremendous technical adroitness. The aquarium accoutrement from NilocG has a unique design and some exciting features which give it the edge over other CO2 diffuser you will find in the market today. Among these features is the inline design which makes it fitting to use this CO2 diffuser/atomizer along with canister filters. The whole set-up of the NilocG Aquatics CO2 diffuser ensure the generation of ultra-fine/ very minute bubbles which are essential for the spread of CO2 in the aquarium space. It is available in two different varieties – one with 1/2” tubing and another with 5/8” tubing. It is made from plastic which means it has an edge over those made from glass particularly when you factor durability. Being a high-performing CO2 ­diffuser, this product requires high pressure to give optimal result you will be happy with.

The NilocG Aquatics CO2 diffuser is one with a touch of class and it would only take going through a few customer reviews to see how highly revered this unique CO2 diffuser is. In a certain instance, a customer can be seen  talking about the impressive rate at which this diffuser dissolves and distributes the CO2 gas; an attribute which was made even pronounced with the emergence of vibrantly colored plants in the aquarium – as emphasized by the user.

Some other customers were also impressed by how they find the NilocG Aquatics CO2 diffuser/atomizer easy to clean and install, and further stressed that it is a good value for every penny spent on it.


  • Very durable
  • Highly efficient
  • Easy to install
  • Great value for money


  • None

5.Fluval CO2 Diffuser:

You do not have to break the bank or spend a whole lot of fortune to get a good CO2 diffuser for you nano tank. The Fluval CO2 diffuser is quite affordable – with the price just under US$10 – and works in a commendable manner to help your aquarium plants blossom [through ensuring the supply of sufficient quantity of CO2]. The Fluval CO2 diffuser is relatively small and simple in design but yet functional, and comes with a ceramic disc which aids the diffusing of CO2 into the waterbody contained in the tank. It was originally made to be used as a replacement part on the 88g Fluval CO2 diffuser but it can be incorporated into other pressurized tanks nonetheless.

One theme that keeps resounding from the words of aquarists that have tried [or are still using] the Fluval CO2 diffuser hinges on its durability with many of them attesting to the fact that it remains intact – functionally and in terms of its components being in one piece – even after several years of usage. On top of that, the fine bubble production from this CO2 diffuser is yet another thing customers have never ceased to talk about with great delight. And, to know that it comes at a very affordable price is viewed as a bonus. All these attributes make the Fluval CO2 diffuser a product to recommend to aquarists with small tanks and on a low budget.


  • Durable
  • Commendable functionality
  • Economical
  • Easy to install


  • Not available for large tanks
  • Not easy to clean

6. Fibst CO2 Diffuser:

There are not so many CO2 diffusers in the class of this very one from Fibst, and the reason it has stolen a match over others is not solely down to the design and functionality.

It is made from 304 stainless steel, a material that is well known for its excellent anti-corrosive capability – but that’s not all; this material also gives the diffuser some sort of shimmer. So, on one hand, you have a very durable product and on the other, a highly efficient piece in the Fibst CO2 diffuser.

Apart from its material make-up, it also possesses a superior ceramic membrane that will generate substantial amount of bubbles which would guarantee the vibrant appearance of your plants while in the aquarium. Additionally, this CO2 diffuser features a suction cup that will ensure easy an secure installation of the whole piece.

It is available in three different sizes/dimensions – 20D X 350L, 30D X 300L and 30D X 350L – and it is perfect for nano tanks.

The uniformity and small size of the bubbles that emerges from the Fibst CO2 diffuser is one of the major reasons a lot of aquarists, that have integrated this device into their tank set-up, have come to cherish it the way they do. In some instances, customers are seen expressing delight over the quality and durability reflected in the Fibst CO2 diffuser.


– Highly durable

– Easy to clean

– Available in 3 different sizes

– Adds beauty/aesthetic thrill to the aquarium environment


– Relatively small surface area which could the rate/rapidity of CO2 distribution

7. Sera Flore CO2 Diffuser:

We shall be ending this review [of 7 top CO2 diffuser] on a big note – saving the very best for the last, you may say – with this piece from the stable of Sera Flore. It is made from top-quality acrylic – this impacts long-lastingness – and is capable of generating 8 – 16 bubbles [with dissolved CO2] in a matter of one second.

The Sera Flore CO2 diffuser can either be mounted outside or inside the tank, and is equipped with features [such as suction cups, brackets and fastener] that are essential in ensuring the secure fitting of the device unto the spot you have chosen to install it.

This is certainly one built for massive tanks as it can be used, without any difficult, in tanks having a capacity of over 600 litres at max.

The quality of the Sera Flore CO2 diffuser speaks for itself and this is one attributes that making it enjoy rave reviews with those (aquarists) who have tried it out attesting to its efficiency in distributing dissolved CO2 at appreciable rate – it has been emphasized [over and again] that the Sera Flore CO2 diffuser makes available the precise amount of CO2 needed for your plants‘ growth at a particular point in time without leaving any avenue for (CO2) wastage.

Again, a couple of customers have rated the Sera Flore CO2 diffuser high for its durability as their device has stood the test of time for years now without any untoward issue.


– Highly efficient

– Durable

– Can be mounted inside or outside the aquarium

– Easy to install and maintain

– Designed for large tanks


– May be noisy while working in some instances

How to set up a CO2 diffuser

As the CO2 diffuser comes in various sizes and designs, so could there be a slight difference in the way they are set up – albeit the principle behind their operation remains the same. More so, a CO2 diffuser can be mounted by completely submerging it in water or installed in-line with canister filters outside the tank.

However, since the CO2 diffuser is only a part of a whole (CO2 system), it is expedient that other parts like the the source of CO2 gas (i.e., CO2 cylinder/bottle) and the CO2 regulator, as well as, bubble counter – which can help you to decipher how well the diffuser is functioning – be installed beforehand.

So, to install the CO2 diffuser, you may first have to soak it in water for some time upon bringing it freshly out of the pack; this especially applies to glass CO2 diffuser. The CO2 diffuser is then positioned in the tank with the aid of suction cup which attaches to the wall of the tank. Prior to positioning the CO2 diffuser, you must have affixed the rubber/silicone tubing to the diffuser. This tubing, which usually comes with the package, will eventually be connected to the CO2 cylinder.

N.B: The CO2 diffuser should be placed as close to the bottom of the tank as possible. Positioning the diffuser at the bottom will result in better absorption of CO2 which makes the gas readily available for plant uptake. Furthermore, the CO2 diffuser should occupy a free space where the flow of bubbles will be undisturbed. However, it is usually recommended that the CO2 diffuser should placed beneath the filter where the water current is strong enough.

Matt Hook

Matt hook has been a passionate aquarist since he was 5 and now he is professional aquarist. Through this blog he plans share his knowledge to beginners. Feel free to contact him if you have any queries.

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