Inspiring Ideas for Modern Home

5 Best Aquarium CO2 Systems of 2023 [Reviewed & Buyer’s Guide]

Imagine waking up to an aquarium with healthy green plants and happy fishes! Sounds great, doesn’t it?

Corals in a Marine Aquarium.

Well, to keep your aquarium healthy, we have the perfect solution. Maintaining an aquarium is not a task if you can get your hands on a good CO2 system. These systems are essential to ensure that the level of CO2 in the tank is optimum, thereby keeping plant and animal life the healthiest.

However, finding the perfect aquarium CO2 system can be quite challenging, given that there are so many options available on the market.

So, to help you out, we have designed this guide with a detailed description of the best 5 options that you can try. You will also find a buyer’s guide after the reviews.

Without further delay, let’s check out the products!

Best Aquarium CO2 Systems

Cartoon freshwater fishes in tank aquarium vector illustration.

Here is the list of the 5 best aquarium CO2 systems that you can use to boost the health and growth of your aquatic life.

1. Fluval Mini Pressurized CO2 Kit - Best for Comprehensive Setups

If you are looking for an efficient CO2 supplementation system for your planted aquarium, Fluval Mini Pressurized CO2 Kit is an excellent option to consider. It can support aquariums as big as 15 gallons. You can rest assured that your plants will stay healthy and green with the support of this system.

Fluval Mini Pressurized CO2 Kit, CO2 Supplement for Planted...
  • Mini Pressurized CO2 Kit for planted aquariums up to 15...
  • Regulator valve effectively controls CO2 output

Why Did We Like It?

This kit is stocked and comes with everything that you might need to set it up. So, you do not have to incur any additional expenses for this purpose. The kit includes use-and-throw CO2 cartridges, a check valve, a gauge, ceramic diffusers, and a connecting hose.

Moving on to the installation, it is as easy as a breeze. If you are new to using aquariums and also to CO2 systems, you do not need to worry at all. It is extremely simple and can be used by beginners and pro aquarists alike.

Moreover, you must know what importance brands hold in the fishkeeping market. And this one is a very trusted company that we can safely vouch for.

It simply means that their customer feedback is great, and they provide one of the best customer services on the market. And coming to their products, you will hardly find any technical glitches. 

What Could've Been Better?

There's no complaint about this product. However, we must say that it is a tad more expensive than its competitors on the market. That said, for the output it delivers, it is definitely worth the price. If you have bought a new aquarium and are on a tight budget, wait for a few days before buying this one.


  • Very easy to install
  • Kit includes all necessary elements
  • Great customer service
  • Cleaning it is very simple


  • A little pricey

Dimensions: 2.7" x 5.4" x 8.1" | Weight: 11.52oz | Power Source: DC | Voltage: N/A | Material: N/A

2. FZONE Aquarium Co2 Regulator DC Solenoid - Best for Budget-Friendly Usage

To ensure that your aquarium does not face any unhealthy algae growth, FZONE Aquarium CO2 Regulator DC Solenoid is an excellent choice. It gives your plants and fishes healthy lives by eliminating all unhealthy and deadly growths in the aquarium. To know more about it, keep reading.

FZONE Aquarium Co2 Regulator DC Solenoid with Bubble Counter...
  • DUAL Big GAUGE! 1.6 inch big dual gauge easy to read your...
  • UPDATED SPLIT-TYPE DC SOLENOID! Newest 12 DC split-type...

Why Did We Like It?

If you are new to aquariums, you might not want to spend a hefty amount on buying CO2 systems.

This product is extremely affordable and also provides great performance. After using it for a while, we have to say that the quality is top-notch and we were very pleasantly surprised because its price was not that high.

Moreover, what really stands out is that it runs on DC power sources. As a result, it draws less electricity, and the power bill will not burn a hole in your pocket at the end of the month.

And because it runs on DC power sources, it is also very simple to plug it into a different socket in case there is a power cut.

Plus, it comes with a bubble counter, making it very simple to understand how much CO2 is flowing into your aquarium. This way, you can moderate it according to the size of the aquarium. 

What Could've Been Better?

On arrival, we noticed that the packaging of this CO2 system was not that great. The kit arrived in boxes that were a little tampered on the sides. We are guessing that during transit, the boxes faced damage. So, it would have been better if the packaging was a little more sturdy.


  • Very budget-friendly
  • Helps save electricity
  • The bubble counter helps to adjust the CO2 level
  • Easy to use


  • Packaging needs to be better

Dimensions: 5.75" x 2.76" x 5.98" | Weight: ‎N/A | Power Source: DC | Voltage: 12V | Material: Aluminum Alloy

3. Decdeal Aquarium DIY CO2 Generator System Kit - Best for DIY Enthusiasts

Are you looking for an option to create an economic CO2 system at home for your aquariums? Decdeal Aquarium DIY CO2 Generator System Kit is the best bet for that. This system is the most budget-friendly option to increase the plants' metabolic rates to enhance faster growth and healthier lives of the fish.

Dec-deal Aquarium DIY CO2 Generator System Kit with Solenoid...
  • ✪【High-Quality Material】Be made of aluminum alloy. It...
  • ✪【Solenoid valve】To control the on and off of CO2...

Why Did We Like It?

Because this system helps generate CO2 constantly through chemical reactions, it is quite important for it to be durable.

And durable it is! Made of high-quality aluminum alloy, it is quite sturdy and lasts for a long time. The caps and pipes are also well-sealed to prevent any form of unnecessary leakage.

Moreover, just like the previous item, this also comes with a bubble counter and a check valve. The bubble counter is extremely crucial for this system as the chemical reactions keep making CO2, and it is very essential that you keep taking readings. Excess amounts of CO2 can be fatal to the fish.

Additionally, their customer service definitely needs a mention. If you face any challenges installing it, their executives will guide you through the process.

In case any of the parts arrive broken, just get in touch with them. They will either get it replaced or initiate a refund. No questions asked! 

What Could've Been Better?

We have hardly any complaints regarding the quality and performance of the product. But those who are new to CO2 systems might face some difficulty installing and assembling them as the instructions are not very clear. You can, however, call up their customer support for help.


  • Made of high-quality materials
  • Help keep track of CO2 level
  • Great customer support
  • Quite simple to clean


  • The user manual is not very detailed

Dimensions: 8.74" x 4.72" x 2.6" | Weight: 9.9oz | Power Source: AC, DC | Voltage: 100V to 240V Input, 12V Output | Material: Aluminum Alloy

4. VIVOSUN Hydroponics CO2 Regulator Emitter System

Among various CO2 systems crafted for petite aquariums, the VIVOSUN Hydroponics CO2 Regulator Emitter System stands out as the strongest contender. Manufactured for easy compatibility with nano aquariums, this equipment ticks all the right boxes in terms of compactness, durability, and functionality. Additionally, it is built with long-lasting brass components, boosting its lifespan while minimizing rusting tendencies.

VIVOSUN Hydroponics CO2 Regulator Emitter System with...
  • Durable Material: Long-lasting durable brass components will...
  • Specifications: 1.58" high pressure gauge: 0-4000 PSI;...

Why Did We Like It?

This VIVOSUN-designed product significantly elevates the level of carbon dioxide in hydroponic systems and planted aquariums, propelling plant growth by an impressive 40%. The kit comprises a precision regulator, flow gauge, industrial solenoid valve, and 5-meter tubing, which together facilitate optimal plant growth and development.

Designed for a USA standard 3-prong plug, the CO2 regulator helps you maintain the ideal amount of CO2 in your aquatic paradise. Its visually appealing look, coupled with its affordability, makes it an attractive choice for both amateurs and seasoned professionals dabbling in CO2 systems.

What Could've Been Better?

Even though VIVOSUN Hydroponics CO2 Regulator Emitter System exhibits superior features, there is room for improvement. The longevity of the metal components could be further improved as they tend to rust over a few years. Furthermore, users have occasionally observed leaks from the regulator that can potentially hamper the product's performance.


  • Durable with high-quality material
  • Enhances plant growth by up to 40%
  • Efficient in maintaining ideal CO2 levels


  • Possibility of rusting over time
  • Potential regulator leakage

Dimensions: 9.06" x 6.81" x 5.98" | Weight: 44.64oz | Power Source: ‎Corded Electric | Voltage: ‎110V | Material: Brass

5. MagTool 4L Aquarium CO2 Generator System

Taking into account price, performance characteristics, and alternatives, we have reviewed the MagTool 4L Aquarium CO2 Generator System and found it to be a comprehensive package for the setup and maintenance of CO2 systems in small aquariums. Despite being slightly more expensive than competing products, the MagTool CO2 System delivers more power and durability with sturdy stainless steel construction, efficient DC power operation, minimal heat generation, and a quiet design.

MagTool 4L Aquarium CO2 Generator System Carbon Dioxide...
  • 4 Liter Capacity. That is 2x larger than the size of our...
  • Professional CO2 Kit With All Accessories Needed For A...

Why Did We Like It?

One of MagTool CO2 Generator's most standout attributes is the product's long-lasting durability stemming from the 4L bottle, which is constructed of stainless steel and takes care of the usage for an extended period. Additionally, it has a capacity for 600-800 grams of raw material, showing its high capacity.

This model has a built-in safety valve that automatically shuts off the system when the pressure exceeds 1137 PSI, enhancing user safety. The system operates on DC power at low voltage, preventing the device from heating up. Not to mention, it has a remarkably quiet design that doesn't hum or vibrate, preserving the peace and tranquillity of your aquarium.

However, this system is noticeably more expensive than similar products on the market. We believe it is justifiable given all the benefits it offers, but we understand it may not fall within everyone's budget.

What Could've Been Better?

While the pack is all-inclusive, it does not include citric acid and sodium bicarbonate needed for CO2 gas production. This could be inconvenient for some users as these raw power components need to be purchased separately. Thankfully, these are readily available and economical, so it's not a major drawback, but it does add an additional step to the setup process.


  • Long-lasting durability with 4L stainless steel bottle
  • High capacity with 600-800 grams of raw material usage
  • Built-in safety valve increases user safety
  • DC power operation prevents the device from overheating
  • Quiet design


  • Higher price range may not be affordable for all
  • Power components sold separately

Dimensions: 17.24" x 10.67" x 7.05" | Weight: 115.04oz | Power Source: DC | Voltage: 12V | Material: Stainless Steel

Best Aquarium CO2 System Comparison Table

ProductDimensionsWeightPower SourceVoltageMaterial
Fluval Mini Pressurized CO2 Kit2.7" x 5.4" x 8.1"11.52ozDCN/AN/A
FZONE Aquarium Co2 Regulator‎5.75" x 2.76" x 5.98"‎N/ADC12VAluminum Alloy
Decdeal Aquarium DIY CO2 Generator System Kit8.74" x 4.72" x 2.6"9.9ozAC, DC100V to 240V Input, 12V OutputAluminum Alloy
VIVOSUN Hydroponics CO2 Regulator Emitter System‎9.06" x 6.81" x 5.98"44.64oz‎Corded Electric‎110VBrass
MagTool 4L Aquarium CO2 Generator System17.24" x 10.67" x 7.05"115.04ozDC12VStainless Steel

Little fish in fish tank or aquarium, gold fish, guppy and red fish, fancy carp with green plant, underwater life concept.

Buying Guide For The Best Aquarium CO2 System

Now that we have discussed the top 5 aquarium CO2 systems, we hope that you have a more clear idea in your head about their features and functions.

However, we have to say that you are only halfway to your destination of choosing the best CO2 system. In order to do that, you have to take a few other things into consideration too. These factors are very crucial in determining how well your CO2 systems would function.

In this section, we will discuss some of those factors. Let's check them out.

  1. The Price

Aquarists sometimes face a dilemma about how to choose the most efficient but economical option when it comes to CO2 systems.

Let us tell you that it does not always necessarily mean that economic ones do not perform well. Quite contradictory, if you research a little and learn the ways to create your very own DIY CO2 system, it can be a very effective option.

There are very good kits that are available on the market and allow you to set up the entire system based on your requirements. You will get all the tools and devices necessary to set it up available in these kits. And it is quite economical too.

However, if you do not want the hassle and also save time, you can go for options that come pre-assembled. But, keep in mind, they are generally a little more costly.

  1. Regulator

Not every aquarium is of the same size, and thus they need different CO2 levels to maintain the healthy life of the plants and fishes.

But then again, all systems are attached to the tanks. So, how do you control the level of CO2 released? Well, you guessed it right: through the regulator!

The regulator helps you to decide the tank’s pressure. But what you need to ensure is that it is easy to control the regulator. Not just the control, it should also be easy to read. If the font size is too small, or if the writings are blurry, you will have a hard time noting the reading.

However, make sure that the gauge and regulator are not too big, as that would ruin the beauty of your aquarium. And lastly, before you decide on buying a kit, do check if the regulator comes with a needle valve.

This is what lets you moderate the level of CO2. In case it is not included in the kit, you will have to buy it separately.

Aquarium CO2 Systems FAQs

  • Is it safe to use a DIY CO2 system for my aquarium?

    For small aquariums and low-budget setups, DIY CO2 systems can be an option. However, they lack the control and precision of commercially designed systems, carry risks of CO2 overdosing, and require frequent maintenance.

  • Can all types of aquatic plants benefit from CO2 supplementation?

    Although most aquatic plants will benefit from additional CO2, certain species, especially those accustomed to low-light, low-CO2 environments, might not show significant improvements. In contrast, high-growth species commonly used in “planted” or “Dutch-style” aquariums can benefit substantially from CO2 supplementation.

  • Does a CO2 system affect the aquarium's pH level?

    Yes, it can. When CO2 dissolves in water, it forms carbonic acid, reducing the pH level. That’s why it’s crucial to monitor your aquarium parameters regularly, including pH, especially when operating a CO2 system.

  • What maintenance does an aquarium CO2 system require?

    Regular maintenance for a CO2 system includes monitoring system components for leaks, checking the CO2 cylinder level, and cleaning the diffuser to avoid clogging. Also, ensure the bubble counter fluid level, and the drop checker solution, is appropriate.

  • Aquarium illustration with fishes stones and plants. Fish tank isolated on white background. Stock vector.


    That's all for today, folks!

    We hope that you had as much fun going through this comprehensive guide as we had while experimenting and writing about the products. After reading this, we hope that you can make a more informed decision.

    But, before saying our goodbyes, we would like to let you in on our favorites. Fluval Mini Pressurized CO2 Kit has managed to stand the test of time and is the best overall.

    If you are looking for a pocket-friendly option, then FZONE Aquarium CO2 Regulator DC Solenoid is the best bet. And if great customer service is your prime concern, then Decdeal Aquarium DIY CO2 Generator System Kit is an excellent consideration.

    And with that, it's a wrap. Until next time, take care!

    Related Articles

    11 Best Aquarium Backgrounds

    11 Best Aquarium Safe Silicone

    11 Popular Small Saltwater Fishes You Need to See

    11 Best Aquarium Sand

    7 Best Substrates for Betta Fish Tank [Gravel, Sand & More]

    10 Best Nano Reef Tank

    13 Epic Pond Fishes Ideas

    9 Best Small Fish Tank