Best CO2 Reactors for Aquatic PLants

Top 10 Best CO2 Reactor & Diffuser for Aquarium

It’s obvious that aquatic plants need carbon dioxide (CO2) to eat, develop, and reproduce. 

As synthetic aquariums do not have the natural cycle of rainfall and evaporation, there’s nothing to stir CO2 into your plant’s water. And as even tablet fertilizers don’t bring CO2 to this closed system, you need to put it in yourself. 

That’s when CO2 reactors come in handy. For your plants to grow, you need to replicate the natural conditions they would grow in. Now let’s have a check on the below list of the most popular CO2 reactors that build a healthy environment for your plants. 

How to Select a CO2 Reactor?

Just injecting CO2 into your tank is not enough. You must have a system that suspends CO2 in the water, refines bubbles to be dissolved, and adjusts the pressure. 

Therefore, before you make any decision, ask yourself what the kit contains. For instance, a CO2 system that includes a generator, diffuser, and regulator will be more cost-effective. 

Several of the features to consider:

  • CO2 bottle: You should select the size of the canister based on the size of your aquarium. A larger bottle will be more durable and cost you less when it needs refilling.
  • Regulator: Adjusts the pressure inside the bottle enabling the CO2 to be released into the water.
  • Diffuser: it is crucial to decrease the size of the bubbles. Finer bubbles have more surface area, enabling more CO2 to dissolve in the water and approach the plants.
  • Bubble counter: Determine the number of CO2 bubbles going to your tank, helping you to track and control the CO2 rate as per what your plants require. 
  • Pressure gauge: Helps you know how much pressure is in the aquarium.
  • Solenoid valve: With a timer, it helps you stop the CO2 release in the water when the time of photosynthesizing elapses. 

As you see, the more functions, the healthier your aquatic system will be, and the less you need to pay for additionals.

The next factor you should consider is whether your reactor provides chemicals to create CO2. Some models enable you only to use CO2 cartridges, while others work just well with chemicals such as baking soda and citric acid. Apparently, the latter is more practical and cost-saving. Generally, consider whether you’ll need to buy these chemicals separately. 

The build’s quality is another vital factor. The housing is often constructed from plastic, glass, or stainless steel. Plastic and glass are more affordable and available in more beautiful designs, however, they’re not as durable as stainless steel. 

You won’t want to end up with a unit that breaks easily. A stainless steel housing is a perfect choice if you want an option that will last a lifetime and prevent any potential hazards. 

Lastly, ensure the model consists of an automatic pressure relief valve. CO2 reactors are closed systems that can explode if the pressure rises. These valves are created to open automatically at a specific pressure level to release fluid if there is too much gas. 

A-List of Best CO2 Reactor for Aquarium

1. Aquatics InLine CO2 Reactor 

Awesome Aquatic Inline CO2 Atomizer Bubble Diffuser Reactor Injector for Planted Aquariums
Awesome Aquatic Inline CO2 Atomizer Bubble Diffuser Reactor Injector for Planted Aquariums

The first option in the list of the best CO2 reactors is Aquatic InLine CO2 Reactor. The sturdy acrylic body offers a high-quality impact response to prevent breakage. 

It’s easy to install the reactor, either inside or outside, with a bracket. As it is an inline unit, it can help get rid of algae that harm your aquatic plants. 

Besides, this unit comes with exceptional Co2 absorption features that are bound to keep your fish and plants healthy. It is recommended to install the reactor with a hose of 16 mm when connecting to a filter or pump. 

Benefits

  • Simple usage and assembling
  • Wall-mount bracket for easy hanging
  • Mitigates algae bloom
  • No need for time-wasting cleaning

Drawbacks

  • Clamps required on all hose connections
  • A bit noisy

2. ISTA CO2 Planted Aquarium Reactor 

ISTA Co2 Reactor & Planted Aquarium Surface Film Skimmer
ISTA Co2 Reactor & Planted Aquarium Surface Film Skimmer

The ISTA CO2 reactor is an ideal option if you’re keeping a small aquarium. It has a compact design, proper for tanks of 10 to 15 gallons. 

This reactor is primarily a surface film skimmer that can eliminate the oil film on the surface of the tank water. It is also considered a makeshift water filter that clogs up with collected debris from the water.

Despite its small size, the device comes with a robust submersible motor. It can displace up to 100 gallons of water every hour. 

Moreover, the unit does not require additional tubing. You just need to put it in your aquarium, plug in the hose from your carbon dioxide tank and turn on the unit. 

Benefits 

  • Easy to install
  • Work as a water filter
  • Able to diffuse CO2
  • Compact construction

Drawbacks 

  • Generate quite big bubbles

3. Sera Flore Active CO2 Reactor 

Sera Flore Active CO2 Reactor 500 - Small 66-160 Gal
Sera Flore Active CO2 Reactor 500 – Small 66-160 Gal

If you’re searching for 100% dissolution of CO2, the Sera Flore Active CO2 unit does a good job of ensuring little to no bubbles enter your aquarium. The reactor makes use of an impeller to boost turbulence when CO2 enters the system. Water turbulence helps facilitate the dissolution of CO2 within the reactor before it is released. 

As it depends on directly combining water and CO2, you have to pair this with a source of CO2 and a pump. The reactor is made for pumps that work on tanks bigger than 55 gallons.

Benefits

  • 100% CO2 dissolution
  • Proper for medium to large planted aquariums
  • No diffuser stone to replace
  • Silent operation

Drawbacks

  • Too strong for small tanks

4. Gulfstream Tropical CO2 Reactor 

Gulfstream Tropical AGU00529 Ista Max Mix Co2 Reactor for Aquarium
Gulfstream Tropical AGU00529 Ista Max Mix Co2 Reactor for Aquarium

The CO2 reactor from Gulfstream Tropical is designed to hold CO2 bubbles continually until they are broken and forced to dissolve into the water. This makes sure there are no bubbles or mist released into the aquarium.

Owing to its sturdy CO2-resistant plastic construction, the introduction of the slight acidity dissolved CO2 does not impact its long-term operation. 

In addition, installing and setting up this reactor is super easy with no tools required. You just need to follow the provided diagrams. 

Benefits 

  • Rated for tanks with pumps that have 250 to 500 GPH of flow
  • No need to replacing a diffuser stone or other components
  • Easy setup

Drawbacks

  • Poor quality control
  • Not really quiet

5. Driak Aquarium Fish Tank CO2 Reactor 

Driak Aquarium Fish Tank CO2 Diffuser Carbon Dioxide Reactor with Suckers for Fish Tank Aquarium
Driak Aquarium Fish Tank CO2 Diffuser Carbon Dioxide Reactor with Suckers for Fish Tank Aquarium

The Driak CO2 reactor is eco-friendly and made from high-grade materials. The silver unit is surprisingly lightweight, facilitating easy handling and installation. Its knurling design also makes it slip-free in wet handling.

The carbon dioxide bubbles generated are small and clear, keeping the environment free of any misty distortion. The reactor produces enough CO2, improving the growth and health of your plants. Besides, the model comes with a suction cup, making it convenient to fix it on your fish tank. 

Benefits 

  • Great for novices
  • Energy-efficient
  • High-quality and safe materials
  • Easy installation and maintenance

Drawbacks

  • Aluminum might corrode over time.

6. WuyouChy Stainless Steel CO2 Reactor 

WuyouChy CO2 Generator System Carbon Dioxide Reactor Kit with Diffuser for Plants Aquarium
WuyouChy CO2 Generator System Carbon Dioxide Reactor Kit with Diffuser for Plants Aquarium

The WuyouChy CO2 reactor is constructed from stainless steel and consists of all the needed attachments and equipment for convenience setup. 

Except for the stainless steel canister that has thick walls and a construction that can take a beating, the valve, regulator and bubble counter are all made of high-grade materials. 

The unit comes equipped with safety valves that open and close at a required time. These safety valves help you control the flow of carbon dioxide entering the aquarium. In addition, the operation is manual and can be set automatically by using the reactor with a solenoid.

It also contains an acrylic diffuser to refine the CO2 bubbles, providing the CO2 time to dissolve and your plants more air to respire. 

Notably, there’s no need to purchase CO2 cartridges as it operates with citric acid and baking soda. The gauge on the reactor will show you how much pressure there is in the aquarium and warn you when to refill. 

It’s vital to note that you should use a funnel and clean threads before refilling to prevent regulator threads from stuck to aquarium threads. 

Benefits 

  • Include a lot of accessories 
  • Good performance 
  • Simple assembling and setup

Drawbacks

  • Not ideal for larger tanks
  • Quite hard to follow the included instructions

7. NilocG Aquatics Inline CO2 Reactor 

NilocG Aquatics | Intense Atomic Inline Co2 Atomizer Diffuser for Planted Aquariums Tanks
NilocG Aquatics | Intense Atomic Inline Co2 Atomizer Diffuser for Planted Aquariums Tanks

The NilocG Aquatics CO2 reactor is made of premium, boosting its durability significantly. It provides an ultra-fine mist of average CO2 bubble size of less than 0.1 mm, which aids in optimal plant thrive. 

Its design is very compact, leaving more space for your fish to swim around. The inline design is also proper for using with canister filters. Besides, it is packed with O-ring seals to guarantee simple maintenance. 

Users can install and mount the reactor below or directly to their tanks. The unit will work best for small to medium-sized aquariums 

Benefits 

  • Able to prevent algae growth
  • Sturdy and highly functional
  • Two-in-one diffuser-reactor
  • Work seamlessly without impacting the flow rate

Drawbacks

  • Not suitable for larger tanks 
  • Use only high pressure rated, acid-resistant tubing

8. Jiawanshun 1X4L Aquarium CO2 Reactor 

JIAWANSHUN 4L Aquarium CO2 Generator System with Timer Solenoid Valve&Diffuser for Aquarium Tank
JIAWANSHUN 4L Aquarium CO2 Generator System with Timer Solenoid Valve&Diffuser for Aquarium Tank

This is considered one of the most well-equipped reactors compared to other units in the list. This complete CO2 generator system comes with a large range of accessories, including gas cylinder, solenoid valve, pressure relief valve, three-stage filter, fine-tuning valve, etc. 

The safety valve automatically decreases pressures as the pressure in the bottles rises up to 70kg/cm. Besides, you can leverage the fine-tuning valve to control the speed of the bubble, depending on your tank’s size. That lets you control the carbon dioxide quantity in the aquarium to guarantee the healthy development of organisms in the aquarium. 

Moreover, the carbon dioxide generator with a solenoid valve can be combined with the lights on the tank after you install the timer. This combination will considerably foster the crazy thrive of water plants, so your tank machine has an ornamental effect. 

Furthermore, the manufacture includes an operating video and operating guides that help you become proficient in the use of the CO2 reactor. Plus, if you worry about excessive carbon dioxide, you can track it in real-time with the help of a CO2 detector. 

Benefits 

  • Very fine CO2 bubbles 
  • Timer controlled panel
  • Sturdy and durable materials
  • Provide tons of necessary accessories

Drawbacks 

  • Pretty expensive 

9. ZRDR CO2 Generator System Carbon Dioxide 

ZRDR CO2 Generator System Carbon Dioxide 2L with Dual Gauge Display Pressure Gauge Automatic Pressure
ZRDR CO2 Generator System Carbon Dioxide 2L with Dual Gauge Display Pressure Gauge Automatic Pressure

If you’re looking for a full-featured CO2 system with a tight budget, the ZRDR CO2 Generator System will be the fit. 

In spite of its reasonable price, everything about this unit speaks of durability and functionality. The reactor consists of all the necessary equipment, including the bubble counter, pressure valve, and the mounting tools and guides manual. 

What’s more, you can work the system with baking soda and citric acid rather than CO2 cartridges. Though you need to buy baking soda and citric acid separately, they’re much cheaper than replacing the pricey CO2 cartilages. 

The pressure valve works automatically, shutting the system down if the pressure exceeds 30kg. In addition, the water-resistant solenoid valve can be connected to a timer so that it can turn the system on and off while you’re out. 

If you’re concerned about the bottle tipping over, the included base makes the bottle more stable, preventing any breakage around the aquarium. 

Benefits 

  • Excellent functions at an affordable price 
  • Come with necessary accessories 
  • Not require special CO2 cartridges 
  • Stainless steel material 

Drawbacks 

  • Produce quite large bubbles, not giving the CO2 enough time to dissolve in the water

10. Yagote Glass CO2 Reactor

Yagote CO2 Glass Aquarium Supply Accessories
Yagote CO2 Glass Aquarium Supply Accessories

The Yagote CO2 reactor can generate rich CO2 to bring aquarium plants with the carbon dioxide they need and enhance the nutrition and health of hydrophytes. 

The reactor is made of premium glass materials, so it can not be easily broken or damaged. Its ceramic diffuser disc includes atomic pores on its surface, creating finer bubbles.  

Additionally, with the included suction cup, it is simple to install and set up the reactor and fix it on the tank firmly. This unit is proper with pressurized aquariums of 15 to 20 gallons. 

Markedly, the Yagote CO2 reactor has high transparency. The fine, see-through glass is blended in the tank environment, which can bring a sense of harmony and unity. Plus, the cylindrical shape and smooth lines help reduce water speed, supporting the dissolution of CO2.

Benefits 

  • Decent design with high transparency 
  • Easy to install into most tanks 
  • Create fine bubbles sufficient for your aquatic plants  

Drawbacks 

  • Belong to the fragile product type

Quick Comparison of the Best CO2 Reactors

#Product NameImagePriceAction
1Aquatics InLine CO2 Reactor Awesome Aquatic Inline CO2 Atomizer Bubble Diffuser Reactor Injector for Planted Aquariums

$$

Buy on Amazon!
2 ISTA CO2 Planted Aquarium Reactor ISTA Co2 Reactor & Planted Aquarium Surface Film Skimmer

$$

Buy on Amazon!
3Sera Flore Active CO2 Reactor Sera Flore Active CO2 Reactor 500 - Small 66-160 Gal

$$

Buy on Amazon!
4Gulfstream Tropical CO2 Reactor Gulfstream Tropical AGU00529 Ista Max Mix Co2 Reactor for Aquarium

$$

Buy on Amazon!
5 Driak Aquarium Fish Tank CO2 Reactor Driak Aquarium Fish Tank CO2 Diffuser Carbon Dioxide Reactor with Suckers for Fish Tank Aquarium

$

Buy on Amazon!
6WuyouChy Stainless Steel CO2 Reactor WuyouChy CO2 Generator System Carbon Dioxide Reactor Kit with Diffuser for Plants Aquarium

$$

Buy on Amazon!
7NilocG Aquatics Inline CO2 Reactor NilocG Aquatics | Intense Atomic Inline Co2 Atomizer Diffuser for Planted Aquariums Tanks

$$

Buy on Amazon!
8Jiawanshun 1X4L Aquarium CO2 Reactor JIAWANSHUN 4L Aquarium CO2 Generator System with Timer Solenoid Valve&Diffuser for Aquarium Tank

$$

Buy on Amazon!
9ZRDR CO2 Generator System Carbon Dioxide ZRDR CO2 Generator System Carbon Dioxide 2L with Dual Gauge Display Pressure Gauge Automatic Pressure

$$

Buy on Amazon!
10Yagote Glass CO2 Reactor Yagote CO2 Glass Aquarium Supply Accessories$$Buy on Amazon!

When it comes to the purchasing decision, the ZRDR CO2 reactor will be an outstanding star, thanks to its more stable base for the canister. Meanwhile, if you already get a base, you can head for the WuyouChy CO2 Generator System. 

Generally, it doesn’t require much work or resources to establish a healthy system for your plant aquarium. A system with high-grade materials, simple setups, and nice safety measures are all that you need, and that’s what both units provide. 

You have a different choice? Please share it with us in the comment section. 

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