The 10 Best Aquarium Co2 Regulators

Looking for the best aquarium CO2 regulator for your planted tank?

The right system will give you optimum CO2 levels.

As a result, it will help your fish and plants thrive while inhibiting algae growth.

To ensure you get the most bang for your buck, we’ve taken the time to carefully review 10 premium CO2 regulators and craft an in-depth buying guide that includes detailed answers to several frequently asked questions.

Contents show

10 Best Aquarium Co2 Regulators

1. CO2 Regulator Aquarium Mini Stainless Steel Dual Gauge Display Bubble Counter and Check Valve


The MOD Complete stainless steel CO2 Regulator features a precision needle valve, bubble counter, and 110-volt solenoid. What’s more, the dual mini gauges provide precise readings from 150 to 2,000 psi. The kit even includes tightening tools.


  • The kit is easy to install thanks to the provided tightening tools.
  • It is compatible with most high-density tubing, atomizers, and diffusers.
  • Spare regulator seal is provided.


  • While easy to read, the dual gauges are prone to freezing up.
  • You need to reinforce connections with Teflon tape to prevent leaks.

2. DoubleSun Hydroponics Aquarium CO2 Regulator


The DoubleSun Hydroponics Aquarium CO2 Regulator is a brass mechanism with a micro-adjustable valve, bubble counter, high-pressure gauge, low-pressure gauge, and 110-volt solenoid valve. You will also receive an O-ring and wrench for fast and secure tightening. Keep in mind this regulator is only designed to thread onto a commercial-sized CO2 tank.


  • The regulator is considerably small, making it a great fit for modest aquariums.
  • It features a luxurious gold finish.
  • The standard CGA320 inlet connection is compatible with most accesories and tanks.


  • The CGA320 inlet valve does not allow you to connect to a paintball cartridge without an adapter.
  • The psi gauge is finnicky.

3. CO2 Regulator with Solenoid Valve and Flow-Meter Emitter


TerraBloom’s CO2 Regulator offers incomparable precision thanks to the flow gauge which emits between one half and 15 standard cubic feet per hour (SCFH) of CO2. The kit includes a 110-volt solenoid valve, a single psi gauge (which reads zero to 4,000), and 15 feet of CO2 tubing. It fits a standard CGA320 outlet.


  • The flow meter comes with a built-in pressure regulator.
  • A greater small starter kit with precision parts and tubing included.
  • It features a 1-year manufacturer’s warranty for defects as well as a 30-day return policy.


  • Almost immediately requires the application of Teflon tape to stop regulator leaks.
  • You will need an adapter if you plan to connect this regulator to a paintball tank.

4. Up Aqua CO2 Regulator with Two Gauges and Adjustable Valve


The Up Aqua CO2 Regulator is a brass device with an adjustable working pressure, a decompressed pressure valve, an electronic solenoid valve, and dual psi gauges. It is workable with a 24-ounce paintball cartridge.


  • The heavy-duty brass construction stands up to moist environments.
  • You can use with large commercial-sized tanks or small paintball cartridges.
  • Instructions are easy to follow.


  • The needle valve is incredibly sensitive.

5. Jili Online Aquarium CO2 Regulator


Jili Online’s Aquarium CO2 Regulator features a durable aluminum construction. Your purchase comes with a precision needle valve, bubble counter, and dual psi gauges.


  • It features a zero to 3,500 psi reading.
  • This regulator is easy to install and maintain.


  • It does not feature an electric solenoid.
  • The magnet valve is not included.

6. Aquarium DIY CO2 Generator System Kit D501 Green & Blue


While not for everyone, the Stong’s DIY aquarium CO2 regulator kit is an interesting solution for planted tanks. It features a blue or green plastic housing, a psi gauge, needle valve, and CO2 tubing. It can be installed in just a few minutes.


  • Takes only 15 minutes to complete setup.
  • Features deformation-resistant tubing.


  • Made from plastic rather than metal.

7. Dolity Aluminum w21.8 Silver Aquarium CO2 Regulator Controller Co2 Decrement Gauge


The Dolity Aluminum w21.8 Silver Aquarium CO2 Regulator comes with two bubble counters and features a single stainless steel psi gauge. Use the needle valve to make fine-tuned adjustments and monitor outputs up to 3,500 psi.


  • Features aluminum construction with stainless steel plating.
  • Comes with an extra bubble counter.


  • Does not feature an electric solenoid.
  • An attractie low-profile piece.

8. Dovewill Aquarium CO2 Regulator


The Dovewill Aquarium CO2 Regulator is an aluminum alloy kit that comes with two bubble counters. It also features an easy-to-adjust precision needle valve and single psi gauge. While inexpensive, it requires the separate purchases of a diffuser and solenoid.


  • Features dual bubble counters for accuracy.
  • Setup is simple.


  • Accesories need to be purchased separately.

9. Up Aqua Aquarium Simple Regulator with Decompress Pressure


The Up Aqua Aquarium Simple Regulator is a preset decompressed pressure gauge (3-4kg/cm2). It features an extremely compact design topped off with a single psi gauge.


  • its small stature makes it easy to conceal in small tanks


  • You cannot make manual adjustments.

10. uxcell Blue CO2 Regulator with Bubble Counter Aquarium Aquatic Plant Tank Equipment


The uxcell Blue CO2 Regulator is a blue-plated aluminum alloy device that comes with a bubble counter and psi gauge. It features precision seals that prevent CO2 from reentering.


  • Sleek design that camouflages itself in planted tanks.
  • This is the most inexpensive option on our list.


  • Accessories must be purchased separately.

Buying Guide

CO2 regulators are crucial components of any planted aquarium. Nevertheless, purchasing the best one can be a complicated process. Below, we aim to answer commonly asked questions about CO2 tanks and their functions.

What are the benefits of using a CO2 regulator in a fish tank?

Plants require CO2 to thrive and grow. While fish give off low levels of CO2 when they breathe in oxygen, it is not enough to facilitate whole photosynthesis. Therefore, planted aquariums require CO2 systems. CO2 regulators help control the volume of CO2 that enters the tank.

How do I control a regulator’s flow?

It is important to make calculated adjustments to the CO2 flow rate. This can be done by moving the needle valve back and forth. Try not to make more than one adjustment each day, as major fluctuations can stress out your livestock. Use your drop checker and bubble counter to monitor the level of CO2. 30 ppm is a good place to start.

Do I need a CO2 regulator with a bubble counter?

Bubble counters measure the number of CO2 bubbles that are released into your aquarium. They may come as a part of your regulator or be sold separately. They allow you to make fine-tuned adjustments to their psi.

Why is my regulator not specifically advertised for aquarium use?

CO2 regulators are used for everything from craft beer making to hydroponics. Therefore, not all regulators are designed specifically for use in an aquarium.

How do I avoid leaks?

If you’re concerned about leaks, fill a spray bottle with soapy water and mist the connections. If the solution bubbles, then you have found yourself a leak. To fix any leaks, wrap connectors with Teflon plumber’s tape and use a wrench to tighten the connection.

Is a CO2 regulator dangerous?

While CO2 cartridges contain pressured gas, they pose very little danger. This is because the gas is inert, meaning it is neither flammable nor explosive. CO2 is also naturally present in the air. As a result, it would take a copious amount to affect a person’s well being. With that being said, ensure that your stem, gaskets, and regulator are free of leaks.

What is a solenoid valve pattern, and why does it matter?

Solenoid valves are small instruments that stop and start the flow of gas. They are often connected directly to an aquarium light timer to ensure that the gas is shut off during low light times. It’s a fairly straightforward piece of equipment that can save you loads of gas and protect your livestock.

Do I need to use a diffuser with my CO2 regulator

Diffusers are small Accessories that attach to a CO2 regulator and break down the gas bubbles so that they disperse evenly. This device helps to ensure CO2 is rapidly dissolved into the aquarium water.

What happens if the CO2 level in your aquarium gets too low?

Plants and fish require CO2 to thrive and grow. The plant specimens in your tank may exhibit stunted growth, ammonia poisoning, and lime deposits without enough CO2 present. What’s more, your tank may become a host to algae blooms and elevated pH levels.

What happens if the CO2 level in your aquarium gets too high?

There is no point in overfeeding your plants CO2. This will simply result in wasted gas. What’s more, excessive CO2 levels can intoxicate fish. They can even cause them to become sluggish and swim erratically.

What size are CO2 cylinders available?

The most common type of CO2 cylinder is the 24-ounce paintball or soda machine cartridges. Typically, these are sold in multiples. Meanwhile, large industrial tanks or multiple tanks may be rigged up to a commercial-grade 5-pound CO2 tank.

Why do the dimensions of my CO2 regulator matter?

While regulators are an imperative component in planted aquariums, their industrial aesthetics often detract from the look of a tank. Thus, ensure that it is not too large.

How do I know if my preowned parts are compatible with my new regulator?

If you already have a handful of accessories on hand, it’s a good idea to ensure your new regulator is compatible with them. CO2 cartridges, diffusers, solenoid valves, etc. are often sold separately.

Are CO2 regulators loud?

When powered up, CO2 regulators are not very loud. With that being said, some machines emit a faint hum while others give off a loud buzzing sound. Most of these noises are no more than a nuisance. Nevertheless, if a sound is accompanied by an inferior performance, it may be time to replace or repair your regulator.

What is a dual-stage system?

Dual-stage regulators reduce the operating pressure (psi) twice. For this reason, they manage to keep control of the pressure even as the capacity of the CO2 cartridge diminishes. Nevertheless, single-stage systems are inexpensive and considered reliable. They just have more of a risk factor.

What materials are the most reliable?

Most valves are made from solid stainless steel or brass. Durable metals ensure that it will last longer. With that being said, the materials for accessory parts differ in quality and consistency.

What is a needle valve and do I need one on my regulator?

A needle valve is also known as a pressure relief valve. It provides consistent control over how much CO2 enters an aquarium. When CO2 cartridges near the end of their lives, their pressures drop. As a result, regulators pull too much CO2, resulting in a large dump that can overwhelm your system. Needle valves prevent this horrific phenomenon and are, therefore, an essential part of a CO2 regulator.

What do the gauges on a CO2 regulator show?

Most CO2 regulators feature two gauges. One is for high pressure, while the other is for low pressure. Low-pressure gauges typically measure between zero and 200 psi. Meanwhile, high-pressure gauges typically measure between zero and 2,000 psi.

How complicated is installation?

Firstly, your CO2 regulator must be connected to an appropriate CO2 cartridge. In most cases, this is as simple as attaching the devices. In rare cases, a connector may be required. Next, the regulator must be connected to the diffuser and bubble counter (if applicable). This can be done using certified CO2 tubing. After that, position the regulator and accessory components inside your aquarium.

What is a drop checker?

A drop checker is a pH test kit that can be inserted directly into your aquarium. It features a small reservoir that contains a pH indicator solution and an air valve that creates a conduit to the tank. When the gauge is submerged in a tank, the existing carbon dioxide becomes trapped in the air valve. As a result, the indicator solution changes color, indicating a healthy or unhealthy concentration of CO2. Some drop checkers feature dual reservoirs for failsafe testing.

What is the recommended CO2 level for a planted aquarium?

Aquatic plants need between 20 and 30 parts per million (ppm). However, this number may be higher or lower depending on the light levels and nutrient density of your aquarium.


We hope you enjoyed our guide and list of products which included the best aquarium Co2 regulator on the market. We’re confident that our list includes the best co2 system for planted aquariums. While it’s not always easy to find a product that fits in your budget and meets your expectations, each one of the products reviewed above is guaranteed to increase the health of your fish and plants.



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