Best Aquarium CO2 Regulators You Need to Buy Now

Aquarium CO2 Regulators Guides
By Garrison Hickles Updated

If you have a planted tank at home and want to make sure they live healthily, then one of the first things you need to do is to provide them with CO2 regulators (carbon-dioxide regulators). When you don’t have an adequate amount of CO2 in your tank, naturally your aquatic plants will die. However, if there is an uncontrollable amount of CO2 in your tank, then it will encourage algae growth, which is of course not an ideal situation.  Not to say, too much CO2 will also endanger the lives of your aquatic pets as well.

Therefore, today, we are going to help you out in selecting the best CO2 regulator for your aquarium, but before we do so, let us try and understand the situations where you need a CO2 regulator and the points you need to keep in mind before making your purchase.

When do you need CO2 Regulators?

First of all, we should tell you that although CO2 is non-toxic by nature; you need to handle it safely. It is a colourless, tasteless and odourless gas that can replace oxygen. A CO2 leak can be dangerous. When it comes out of a compressed cylinder, it automatically transforms from liquid to gas. Since the gas is -110° F (-78° C), it can cause tissue damage. So, be cautious. In addition, you would get a shock if you open the valve on an unregulated cylinder as it generates a very strong static discharge. Therefore, please maintain all the safety guidelines while handling a CO2 regulator.  

Okay, as you all know plants get their nutrition through photosynthesis. For this, they need CO2. In the wild, they get this supply of CO2 from their ambience. Unfortunately, in a closed environment, the supply of CO2 is limited as tap water is depleted of it.  

This is why you need to supply CO2 to your tank with an injector. However, it is important that you regulate it. Not only will it save your money, but you will also be able to make sure that it doesn’t lead to algae bloom or suffocate your aquatic pets.

Now, you may be thinking about how much CO2 is adequate for your tank. Well, to determine that, you can take the help of a drop checker. It is made up of plastic or glass and has a solution in it. When you put it in your tank, CO2 from the tank water will leak into it, thereby helping the solution change its colour. This is what the various colours of a drop checker signify:

  • Yellow – Too much CO2
  • Green – Perfect amount of CO2
  • Blue – Insufficient CO2

The amount of CO2 that your tank needs would depend on the following factors:

  • The volume of your tank
  • Number and type of aquatic plants in your tank
  • Number of aquatic pets in your tank
  • Amount of water movement
  • How much light your aquatic plants are being exposed to

Note: Enough CO2 is produced by fish respiration, surface agitation and organic breakdown of dead plant matter. So, you don’t always need a CO2 injector. However, having one helps improve the life of your aquatic plants. Medium and high-lit plants need a lot of light and CO2.

Alright, now that you have an idea of why you need CO2 regulators for your tank, let us shift gears and focus on the things you need to keep in mind before buying one.

Things to keep in mind Before Buying a CO2 Regulator

Before you make your final decision regarding which CO2 regulator to buy, you need to keep in mind the following factors:


Most CO2 regulators are pretty easy to install and use. It basically involves connecting a few tubes and turning a bunch of knobs. To get to the right amount of CO2 for your tank, you would have to fine-tune and adjust for a couple of times before finding the exact right amount. However, you don’t want to deal with a regulator that is too tough to handle.  


How easy is your regulator to read is another component you need to bear in mind while making your purchase since it obviously would help you gauge whether the amount of CO2 in your tank is appropriate or not.


You need to make sure that the CO2 regulator you are buying is compatible with your CO2 cylinder. This is especially true if you are using your regulator for different tanks.  For single tank usage, a regulator that is compatible with normal paintball cylinders (24 oz) works well.

Type of Material

It is crucial that the regulator that you buy is made of durable material so that it lasts for a long period. Usually, CO2 regulators made of stainless steel or brass are good choices.  

Type of Kit

Different companies provide different items in their CO2 regulator kit. Try and make sure the one that you buy comes with a needle valve as it will give you precise control over the flow of CO2 entering your tank. It also must have a solenoid valve since it will save you from wasting CO2 during “light-off” hours (when your plant no longer need CO2).

Other items that you should look for in your kit are bubble counter, check valve, gauge, tubing and washer.

Number of Stages

CO2 regulators can be of two types – single or dual. A single-stage regulator knocks off the pressure down to a constant PSI. A dual-stage further prevents any fluctuations in the PSI. Although a single-stage regulator can get the job done, having a dual-stage regulator will minimalize any risk associated with the final output.

Alright, that is enough of a preparation that you would need for buying a CO2 regulator. Let us find out which ones are the best in the market.

The 5 Best CO2 Regulators for Your Aquarium

We spoke to industry experts and did extensive market research for creating this list. Mind you, this is not a ranking. The following regulators are not listed in any order. Whichever suits your needs, you need to pick that one. These five CO2 regulators have stood out among the rest.

Aquarium CO2 Regulator with Solenoid 110V-Mini Dual Gauge Display Bubble Counter

Build of highly durable materials, the Aquarium CO2 Regulator with Solenoid 110V-Mini Dual Gauge Display Bubble Counter is compatible with almost all high-density tubing. Moreover, it functions perfectly well with a bunch of different diffusers and atomizers.

Another great aspect about this regulator is that it has a great display which allows you to read the amount of CO2 from 150 to 2000 PSI. In addition, it also comes with an energy-saving solenoid valve that is noise-free and works at a low temperature, thereby making sure your aquatic pets aren’t disturbed.  It also adds to the life of your regulator. Extremely easy to install, this is one reliable regulator that you can purchase.  


  • Durable
  • Energy-saving solenoid valve
  • Extra seal ring
  • East installation
  • Consistent
  • Reliable
  • Wide range of adjustments (150-2000 PSI)
  • Compatible with most high-pressure tubing, diffusers, and atomizers.


  • Bubble counter doesn’t rotate.

VIVOSUN Hydroponics CO2 Regulator Emitter System

The VIVOSUN Hydroponics CO2 Regulator Emitter System is known for its efficiency in maintaining an optimal level of CO2. It helps in keeping the perfect balance between the growth of your aquatic plants and in stopping algae growth.

It is one of the most budget-friendly regulators that you can buy currently. However, don’t think that just because it is affordable, it lacks in quality or design. It scores really well in both those departments.  Built with metal, it comes with an electric solenoid valve.

It can operate from 0 to 4000 PSI, which is a pretty wide range. Besides, its inlet connection of CGA-320 and flow meter of 0.5-15 CFH is pretty impressive as well.  You will also find a plastic air hose and a standard power cord in its packaging.


  • Affordable
  • Complete control of the flow
  • Durable
  • Wide PSI range
  • Comes with a plastic air hose
  • Features a power code


  • Boisterous humming noise

JARDLI Aquarium CO2 Regulator with Solenoid for Planted Tank

Built with high-quality aluminium, the JARDLI Aquarium CO2 Regulator with Solenoid for Planted Tank comes with a stainless steel diaphragm. It contains a CGA 320 thread connection stem adapter and a CO2 paintball adapter. Besides, it can be used with CO2 cartridges as well.

The solenoid valve that comes integrated with it can operate with low power consumption and is not only quiet in operation but stays cool temperature-wise. You will be able to fine-tune adjustments with its precision needle valve and locking mechanism. It is suitable for 5-400 gallon tanks.

Since it has a large knob, it is very easy to operate this product.  It can even work with 360° swivel piping.


  • You can fine-tune adjustments from 0-70 PSI.
  • Comes with a paintball adapter
  • Features a CGA 320 thread connection stem adapter
  • High-quality aluminium body
  • Stainless steel diaphragm
  • Suitable for tanks of almost every size (5-400 gallons)


  • Expensive

CO2 Aquarium Regulator Mini Dual Gauge Display

The CO2 Aquarium Regulator Mini Dual Gauge Display is one of the easiest regulators to operate.  It features a knurled knob which helps in making fine adjustments. The dual gauge display of this product is extremely easy to read and notifies you about the level of CO2 in the aquarium and the outlet pressure.

The one-way valve helps in preventing water from flowing into the cylinder, thereby keeping it safe. This also ensures that the bubble counters remains not only accurate but also consistent.

This product has been specifically designed for planted tanks. Built with aluminium, it is highly durable and has a working pressure that extends till 75 PSI.  You would also get extra O-rings and a wrench with this product.


  • Specifically designed for planted tanks
  • Highly precise adjustments
  • Includes extra O-rings and a wrench
  • Clear display


  • Only suitable for side open US standard CO2 bottles with CGA 320 interface.

DoubleSun Hydroponics Aquarium CO2 Regulator

The DoubleSun Hydroponics Aquarium CO2 Regulator is made with high-quality materials and is built to last for a long period. Since it is constructed with a decompressing pressure gate, it is extremely easy to adjust. It is also very stable and accurate.

It comes with a dynamic range of 150-2000 PSI. You can fine-tune the release of CO2 with its precision-discharged valve. Another advantage of this regulator is that it is extremely customizable, which makes it very versatile.

With a metal body, the valve framework is produced with the help of industrial electric solenoid. Besides, it comes with a nylon washer and a pressure meter.


  • Durable
  • Highly customizable
  • Easy installation
  • Double stage ensures safety


  • Expensive


So, as you see, the importance of CO2 regulators is extremely high in planted tanks. It may not seem mandatory initially, but for the long run and the health of your aquatic plants, you must get this installed as soon as possible. Be sure to follow our guidelines and instead of going with fancy items, focus on which one will be durable and efficient in the flow of CO2 to your tank.

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