Selecting the best aquarium CO2 regulator can help you significantly improve your aquarium’s ecosystem quality.

Many options available in the market have a low build quality with faulty valves and gauges, and they also suffer from leakage. These possible issues make finding a perfect CO2 regulator a rather challenging task.

So to help you out, we tested dozens of CO2 regulators for aquariums and compiled our favorite ones into a list. It doesn’t matter if you’re a beginner looking to set up your first fish tank or a long-time aquarist looking for an upgrade; you can find suitable options below.

Comparison Chart

Products Dimensions (in Inches) Weight (in lbs) Maximum PSI (on Gauge)

3.5 x 3 x 4.5 1.05 1,500
SR Aquaristik Dua-Stage 12.68 x 9.13 x 7.17 5.15 4,000

9.6 x 7 x 3.6 2.85 3,500

5.5 x 4.5 x 5 2.8 3,500
VIVOSUN Hydroponics

12.56 x 9.69 x 6.65 2.75 4,000

Handpicked Reviews of the Best Aquarium CO2 Regulators

1. AQUATEK CO2 Regulator Mini


  • Very compact and portable
  • Easy assembly
  • No adapter is required


  • Not suitable for larger tanks due to its small size

AQUATEK’s CO2 Regulator Mini is a great device that is jam-packed with helpful features. It is a premium quality product and is a popular choice among aquarium enthusiasts. It is an excellent option for you if you are looking for something that can be hidden or fitted in a small tank without requiring a complex setup.

Its compact design utilizes precision needle valves to fine-tune the flow of CO2 according to your aquarium’s needs. It also comes with a bubble counter that lets you monitor the flow and a small check valve that prevents water’s back-flow when the pressure is turned off.

It is equipped with a solenoid valve which allows you to connect the regulator to a timer that can automate the flow of CO2. You can set the device so that CO2 is pumped only when it’s daytime or when you turn on the lights so that your plants can prepare their food easily via photosynthesis.

AQUATEK’s CO2 regulator comes with heavy-duty electrical wiring, making it handle extended workload periods without shorting out. Furthermore, when you eventually run out of CO2, you can easily replace the cylinder with standard paintball CO2 tanks without needing an adapter or additional plumbing.


The AQUATEK CO2 Regulator Mini is one of the best mini CO2 regulators in the market. It offers everything you will need for a basic aquarium and comes in a small size that can fit anywhere with ease. It is an excellent choice for both beginners as well as long-time aquarium owners alike.

2. SR Aquaristik Dua-Stage CO2 Regulator Kit


  • Dual gauge structure that shows both working pressure and tank volume
  • Built-in safety valve which will automatically release pressure if it is too high
  • Large control output knob and gauge for easy usage


  • Quite large and heavy as compared to other regulators

The SR Aquaristik Dual Stage CO2 Regulator is a heavy-duty device built for larger and full-fledged aquariums. It offers a unique dual-stage CO2 regulation system designed to reduce the pressure in two stages to provide smoother and consistent carbonation of the aquarium water.

It is a safer option compared to single-stage regulators because they run the risk of releasing large amounts of CO2 in the water at once, which can harm your fish. This regulator is also equipped with a safety valve that controls the pressure. If it exceeds a specific safety limit, the valve will open and automatically reduce the excess amount.

SR Aquaristik offers various indicators with their regulator that will keep you updated with helpful information such as CO2 output and canister pressure at all times. These indicators make the regulator very easy to use.

It also offers a bubble counter with a built-in check valve so you can manage the exact number of CO2 bubbles going into the aquarium. Along with this, the regulator has a solenoid valve, ensuring that you have everything you need to manage the CO2 supply in your aquarium efficiently.


SR Aquaristik’s CO2 regulator is made while keeping the safety of the user and their aquarium in mind. Aside from all the protective features, it offers you precise control over the flow of CO2 and multiple gauges to keep track of it. It is best suited for fully-fledged tanks. However, its large size might make it incompatible with small aquariums.

3. FZONE Aquarium CO2 Regulator


  • Premium build quality
  • Air-tight sealing to avoid leakage
  • Silent operation


  • Pressure is not adjustable
  • Slightly on the heavier side

FZONE’s Aquarium CO2 Regulator is a silent, energy-efficient device that comes with a very reasonable price tag. The highlighting feature of this device that separates it from other CO2 regulators is its DC solenoid technology.

A common problem with AC solenoids, apart from being loud, is that they carry the risk of burning out if they malfunction. It is not the case with the FZONE CO2 regulator, as it uses a split-type DC solenoid that consumes as little as 12V of electricity. This system is more stable, safe and reduces electricity usage and noise output, making it the perfect upgrade.

It comes with all the tools in the box that makes the installation time-saving and easy, which can be very helpful for beginner aquarists. Along with this, the regulator also uses precision needle valves that help improve control over the flow of CO2 in the tank.

It is built with highly durable materials, such as stainless steel, which will not rust underwater. This feature reduces the chances of any unwanted leaks or cracks. The regulator body is made from an aluminum alloy, while the needle valves and gauges are made from electroplated copper and stainless steel for maximum strength.


This CO2 regulator from FZONE is an excellent device to improve the CO2 quality without having to worry about leaks or breaks. It offers advanced features such as a split-type DC solenoid that will be a huge benefit thanks to the reduced sound and electricity usage.

4. Premium AQUATEK CO2 Regulator


  • Made from brass, making it very durable
  • Compatible with most tubing and devices
  • It has a cool-touch industrial solenoid design


  • The needle valve is difficult to tune precisely.

AQUATEK’s Premium CO2 Regulator is an excellent option for beginner aquarists, as it is very easy to use. It is a well-constructed device that feels very durable and offers many helpful features.

This regulator has all the monitoring controls you’ll need, such as a bubble counter and cool-touch solenoid valve housed in its corrosion-resistant and industrial-grade brass body. The device is also able to connect to paintball CO2 tanks without requiring additional plumbing or adapters.

It is compatible with most high-density tubing, so you don’t have to worry about making aftermarket purchases. AQUATEK’s CO2 regulator can also work with most CO2 atomizers as well as diffusers available in the market, sparing you the trouble of finding suitable devices.

The CO2 pressure regulators and precision needle valves allow you to fine-tune the pressure. However, the controls feel slightly flimsy and delicate, so you should avoid turning them too hard.


This CO2 regulator is great for people who want to avoid the hassle of buying multiple tubes and devices and want a sturdy regulator that can last for a long time. It offers all the essential features you will need, but the valve may not be as precise as other regulators.

5. VIVOSUN Hydroponics CO2 Regulator


  • Long-lasting and durable build quality
  • It comes with all needed components such as tubing
  • Affordable


  • Only has a single gauge

This CO2 regulator from VIVOSUN offers the perfect set of features for most aquariums and even other purposes such as garden houses or grow rooms. It is built in a brass finish that is very appealing to look at and also highly durable.

It comes with tubing, wiring, flow gauge, a standard 3-prong plug, and everything you will need right out of the box. All the parts are easy to set up and offer superior quality at an affordable price point.

However, it only has a single gauge that shows the CO2 pressure, unlike other options that provide multiple gauges for monitoring the pressure. That being said, the display is precise and clear, making it easy to read and understand.

It also comes with a high-quality solenoid valve similar to high-end options. However, it lacks a bubble counter, making it slightly more compact but reducing many aquarists’ overall useability.

It can sustain up to 4000 PSI of pressure, making it perfect for regulating the CO2 levels in aquariums of all sizes and types. It is proven to increase the growth rate in aquarium plants by up to 40 percent and is also suitable for other purposes such as growing tents and greenhouses.


The VIVOSUN Hydroponics CO2 regulator has almost all the features you need in a durable and appealing package. It is great for people who need something to get the job done without the fancy bells and whistles.

Things to Consider While Choosing the Best CO2 Regulator for Your Aquarium

Following are a few key points you should keep in mind while purchasing a CO2 regulator for an aquarium:

  • Valve/Bubble Counter Precision

CO2 regulators have at least one gauge and valve if the pressure is adjustable. It can move up to having three or even more gauges depending on the type of regulator and the features it offers. These valves and gauges allow you to see and control the amount of CO2 entering the aquarium and are an essential part of the device.

Making sure the valves and gauges in a CO2 regulator are precisely working is very important. If these parts are not perfectly in tune, you may not see the correct readings, leading to problems such as injecting too much or too little CO2 into your tank, which can be very harmful. This reason is why it’s best to buy a CO2 regulator with a bubble counter.

  • Build Quality

One of the most important things to consider when selecting a CO2 regulator for your aquarium is the build quality. This is because they are under the constant strain of the surrounding water and pressure from the carbon dioxide gas inside them. Any leak or crack can end up dissolving excessive CO2 in your tank that can cause CO2 poisoning in your fish and plants.

By spending a little extra money, you can get a lot more in return by making your CO2 regulator a worthy one-time purchase for your fish tank. Some of the best materials you can look for in a regulator are brass, stainless steel, aluminum alloys, and other treated metals.

You should also keep an eye out for the hose that carries the gas from the cylinder to the tank. People generally tend to ignore this part as these hoses are very easy to replace. However, you need to check whether these lines are meant to carry CO2 or not, as not all of them are. Additionally, make sure that there are no bends or dents in the lines that can cause them to break prematurely.

  • Solenoid Valve AC/DC

Having a solenoid valve makes a CO2 regulator easier to use and allows you to set up a personalized timer system. Even though not having a CO2 regulator with solenoid is not a deal-breaker, it is still a valuable addition that can help automate your CO2 regulator. For example, you can use the solenoid to set the regulator up with your aquarium lights so that the regulator turns on when the light is on and also turns off with them.

Most regulators come with AC solenoid valves as they are less complicated and inexpensive. However, sometimes they produce a very weak humming noise and can get very warm over long hours of use. They also consume more power compared to DC solenoids.

On the other hand, DC solenoid valves are more durable, safe, and sturdy. They can control the regulator for longer periods without using as much electricity and do not produce any sound.

But just like the AC solenoids, they have some downsides too. Even though they run very efficiently, DC solenoids are complex machines that are very hard to repair and are also expensive. Additionally, they do not have any battery indicator, so it’s very hard to predict when their batteries need to be replaced ahead of time.

Do You Need a CO2 Regulator for Your Aquarium?

CO2 is the prime ingredient that makes it possible for plants to make their food. In natural environments, plants get their dose of CO2 from other dead and decaying plants and also the ocean bed.

However, in an artificial ecosystem, getting this CO2 is very hard for them as the water is depleted from CO2, and there is no decaying matter present in the tank. This problem is why you need to inject supplementary CO2 to balance their needs and enable them to make their food.

Now you can think of CO2 as steroids for your aquarium, and as we all know, too many steroids can be very harmful. Increased levels of carbon dioxide can not only cause CO2 poisoning, but it can also lead to the overgrowth of the aquarium plants.

Excessive CO2 also supports the growth of unwanted algae and other bacterias that can degrade the quality of your aquarium as everyone starts fighting for the same resources.

FAQ: Best Aquarium CO2 Regulators

Here are a few common questions people have when looking for a CO2 regulator for their aquarium:

Are CO2 Regulators Important?

CO2 regulators are very important for aquariums and other purposes such as grow rooms and greenhouses. It is because CO2 itself is necessary for plant life and for photosynthesis to take place. They help control the flow and pressure of CO2 in your tank so that your plants have no trouble preparing their food.

Since fish exhale CO2 during the process of respiration, a certain quantity of CO2 is always present in our tanks, but this usually isn’t enough for optimal plant growth. This is where CO2 tanks and regulators are used as they mechanically add CO2 to boost the photosynthesis process and achieve bushier plant growth.

Most plants used in aquariums prefer a CO2 level of around 10-15ppm (part per million). Anything less than this might not be enough to support the plant growth while having too much CO2 can be dangerous for the fish. This problem is why it is not recommended to add CO2 in your tank without appropriate regulators.

Where Should I Place the CO2 Regulator in My Aquarium?

CO2 regulators have to be used with CO2 tanks and are often used with diffusers and other related devices. Due to the size of these devices and the large amount of tubing needed to connect them all, CO2 systems tend to take up a lot of space.

Thus, the best place for the regulator is usually next to or just above the aquarium itself. It allows the regulator to be easily connected to the tank without directly intruding on the tank space. There is no set rule, and you can always go ahead and experiment with different positions to find whatever suits your aquarium best.

How Long Should I Run CO2 In My Aquarium?

You should run CO2 in your aquarium for about 8 hours a day if you have plants that require a lot of sunlight and about an hour or two if your aquarium has low-lit plants. It’s best to run your regulator in intervals throughout the day to maintain a constant level.

The best way to set up timings for your aquarium’s CO2 is by using a regulator with a solenoid valve. It will allow you to set up the device to a specific time, saving you from the hassle of turning it on manually.

A good rule of thumb is to start your CO2 about an hour or so before your lights turn on.

This allows enough CO2 to build up in your tank before the lights turn on for your plants to begin photosynthesis right away. On the other hand, you can always keep it linked to the lights, but this usually takes some time for the plants to begin photosynthesis properly.

Does CO2 Regulator Size Matter?

CO2 regulator size is not very important when it comes to aquariums. The purpose of a CO2 regulator is to control the pressure and flow of CO2 into your tank to make sure that it stays in a specific range. It is done using valves that block airflow allowing only a specific amount of CO2 at a time.

This feature is why the size of the regulator itself is not a significant factor as long as it can provide the same features as larger ones. For example, if a smaller regulator can handle the same PSI and has all the features you need, it will be providing you with the same quality while taking up less space.


It is crucial to have good quality and trustworthy CO2 regulators to ensure that your aquarium’s fish and plant life stays healthy.

Choosing the wrong regulator can make a hole in your pocket for no reason and damage your aquarium’s flora and fauna.

If you want to go for the best CO2 regulator for planted aquariums, we highly recommend the AQUATEK CO2 Regulator Mini. It has everything you need from a regulator, such as a bubble counter, solenoid valve, and accurate gauges.

Even with all this, it is very compact and easily fits into even the smallest aquariums. Additionally, it is affordable and offers a premium build quality that makes it our best choice for an aquarium CO2 regulator.

5/5 - (14 votes)


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