10 Best CO2 Regulators for Fish Tanks

BEST OVERALL

FZONE Aquarium CO2 Regulator

PREMIUM CHOICE

AQUATEK CO2 Regulator Mini

GREAT VALUE

DoubleSun Aquarium CO2 Regulator

As we’re sure you know, carbon dioxide plays an important part in the photosynthesis process and the supply of oxygen. CO2 is essential for the growth of plants, so if you have a planted aquarium, you’ll want to make sure that your plants are exposed to the right amount of carbon dioxide. However, that’s hard to do on your own, so you’ll need a reliable CO2 regulator to help you determine the right dosage for your tank. There are numerous CO2 regulators on the market and it can be hard to determine which one is the best for you. That’s where we can help.

Table of Contents

BEST OVERALL

FZONE Aquarium CO2 Regulator

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This product offers triple stage regulation, meaning that it can sustain high pressure levels without releasing the excess CO2 in the water, which secures your aquatic environment if things get out of hand. Working output pressure can be adjusted from 0-60 psi, and the flow rate won’t change. This regulator comes with a solenoid valve, which will turn on and off when the timer alerts it, and it won’t overheat even if it works for several hours. Also, the needle valve is very precise and due to its rotating ability, you can install it on both top opening and side opening cylinders . The product includes a bubble counter, a readable pressure gauge, and a paintball adapter, which makes it compatible with CO2 cartridges. This is a sturdy regulator made of aluminum alloy and its compact size makes it suitable for aquariums of all sizes. It comes with all the tools necessary to set it up.

What We Like Most

Triple stage regulation

Solenoid valve with a rotating needle

Includes a bubble counter, gauge, and a paintball adapter

Compact size

All installation tools provided

Our Synopsis:

This is one of the best and most affordable products available on the market. It comes with a triple stage regulation and all the things you need to set up an efficient CO2 regulator in your fish tank.

Analyst Rating

PREMIUM CHOICE

AQUATEK CO2 Regulator Mini

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This regulator comes with a quality solenoid design and it’s made of resistant materials, which makes it a worthy investment. It includes a bubble counter with an integrated check valve, and it comes with a high-precision needle valve that enables releasing just the right amount of CO2. You can adjust the flow rate. This product is compatible with the majority of the CO2 atomizers and diffusers, as well as with most high density tubing. You can easily connect it to a paintball CO2 tank, without the use of an adapter. It comes with dual gauges, the left one measuring the tank’s capacity, and the right one measuring output working pressure, and both of them are clear and easy to read. This regulator’s compact size makes it ideal for smaller, planted, freshwater aquariums.

What We Like Most

Made of resistant materials

Bubble counter with integrated check valve included

High precision needle valve

Dual gauges

Compatible with most CO2 atomizers and diffusers

Our Synopsis:

This is a highly efficient CO2 regulator that can be installed easily, as all tools are included. Its compact size makes it suitable for any fish tank.

Analyst Rating

GREAT VALUE

DoubleSun Aquarium CO2 Regulator

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This product is made of strong steel, and the valve framework is made of industrial solenoid, which not only ensures durability, but it’s also designed to withstand high pressure levels reaching up to 2000 psi. Maximum output pressure is 45 psi. It has a decompress pressure gate for extra security and it’s easy to adjust. This regulator includes an accurate needle valve that enables stable CO2 output. The solenoid, low-temperature valve operates in silence and it saves energy. The regulator has dual gauges that provide accurate readings of inlet and output pressure. Also, you can modify the flow rate according to the needs of your aquatic pets. This CO2 regulator works well with most types of high density tubing and it’s compatible with the majority of CO2 atomizers and diffusers. It’s easy to install and it comes with all the necessary tools.

What We Like Most

Dual stage regulation

Made of strong steel

Includes solenoid valve and a reliable needle

Dual gauges

All installation tools included

Our Synopsis:

This is a budget-friendly and reliable choice for aquarium CO2 regulators. It’s easy to install and it comes with all the accessories necessary to set up an efficient CO2 system and keep your plants growing.

Analyst Rating

4

SR Aquaristik CO2 Regulator

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This CO2 regulator provides additional safety when it comes to the release of carbon dioxide due to its dual stage regulation. It comes with a large control output knob that significantly reduces the risk of accidentally changing the amount of CO2 that gets released and it has extra regulator seals. This product includes an electronic solenoid with LED light to make it easier to see when the system is on and off, and you can use it with a timer or a pH controller. Also, the regulator comes with a bubble counter with an integrated check valve and dual gauges that are easy to read. This CO2 system works well for planted aquariums or as a carbon dioxide supplier for calcium reactors for aquarium reefs. It comes with all installation tools and it’s easy to set up.

What We Like Most

Dual stage regulation

Electronic solenoid with LED light

Includes a bubble counter with a built-in check valve

Dual gauges

Easy assembly

Our Synopsis:

This is an excellent choice for CO2 control because it provides dual stage regulation. It’s easy to install and it comes with all the items necessary to release just the right amount of CO2 and keep it consistent at all times.

Analyst Rating

5

FZONE Aquarium CO2 Regulator

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This CO2 system provides dual stage regulation and it comes with a high precision needle valve that allows you to easily adjust the flow rate. It includes a customized, DC split-type solenoid that doesn’t overheat or create noise, and it allows the valve to open and close smoothly. This product also includes easy-to-read dual gauges, so that you can monitor the inner and outer pressure, and a bubble counter with a built-in check valve to prevent the backflow of fluids from getting into the solenoid. The inner pressure ranges from 600-1100 psi, and the output pressure is preset at 45 psi. The regulator’s body is made of aluminum alloy, while gauges are made of stainless steel, so you can expect a durable construction. Also, the sealing materials have been upgraded to withstand temperatures ranging from 45 to 90 degrees Fahrenheit, reducing the risks of leakage.

What We Like Most

Dual stage regulation

Power-saving, low-temperature solenoid

Dual gauges

Bubble counter with a check valve included

Upgraded sealing technology

Our Synopsis:

This CO2 system is easy to install and it’s made with durability in mind. It comes with everything you need to control CO2 levels in your fish tank, from clear dual gauges to a bubble counter and a reliable and accurate needle valve.

Analyst Rating

6

S.T. International CO2 Regulator

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This is a pricier option, but it offers a lot in return and it comes with a 2-year warranty. It’s designed with a decompression gauge that ensures steady and accurate release of CO2. This product’s unique feature is a solenoid magnetic valve, which was first patented and designed by this company to ensure stable and reliable CO2 regulation. The solenoid shuts down and turns off the regulator as programmed, so you can rely on effective CO2 injections even when you’re absent. This regulator provides a silent operation and it doesn’t overheat, so it won’t disturb your aquatic pets. It comes with a standard connector for a CO2 tank, and if the connector is removed, it can be used with disposable cartridges.

What We Like Most

Single-stage regulation

Solenoid magnetic valve

Silent operation

No overheating

Compatible with various cylinders

Our Synopsis:

This CO2 regulator is an excellent choice for larger, planted aquariums. It provides reliable output of CO2 and, although it falls under more expensive options available, it’s designed with longevity in mind.

Analyst Rating

7

VIVOSUN Hydroponics CO2 Regulator

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This CO2 regulator will provide optimal plant growth and it can be used in indoor grow rooms, tents, and green houses, in addition to aquariums. It’s made of durable brass and it’s less prone to rusting. It’s also one of the more affordable options on the market. This CO2 system includes a precision regulator, industrial solenoid valve, and a flow gauge. It also comes with a plastic washer, a 5-meter plastic dispensing tubing, and a US standard plug. All installation tools are included and you’ll have no trouble setting it up by following the instruction manual. It’s designed to release a steady flow of CO2 and the high pressure gauge reads up to 4000 psi. The flow meter reads from 0 to 15 SCF per hour.

What We Like Most

Made of durable brass

Includes a solenoid valve and a flow gauge

Can be used in tents, green houses, and aquariums

Comes with plastic dispensing tubing, a washer, and a US standard plug

All installation tools included

Our Synopsis:

This is a highly efficient CO2 regulator that can significantly speed up the growth rate of your plants. It’s easy to install, it’s made of resistant materials, and it has a high-quality solenoid valve.

Analyst Rating

8

ZRDR CO2 Regulator Aquarium

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This CO2 regulator is one of the more affordable options and it features a DC split-type solenoid that works on a low temperature, doesn’t produce any noise, and it reduces power consumption. It comes with dual gauges that clearly show the working status of the regulator, so you can immediately see if there is too much or too little volume. This product also includes a bubble counter with a built-in check valve, and fine-tuning is made easy thanks to the precision of the needle valve. You can also adjust the output pressure that ranges from 30-60 psi. The regulator is made of aluminum alloy, which makes it durable and less prone to rust. It’s compatible with most brands of high density tubing, CO2 atomizers and diffusers.

What We Like Most

Dual gauges

Noise-free, power-saving solenoid

Includes a bubble counter with an integrated check valve

Made of aluminum alloy

Compatible with high density tubing and most CO2 atomizers and diffusers

Our Synopsis:

This is a good choice for CO2 control in fish tanks. It’s a durable product that comes with a high-quality solenoid and a precise needle valve, and it’s easy to install.

Analyst Rating

9

Titan Controls CO2 Regulator

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This CO2 system comes with a heavy-duty solenoid valve and a high-quality, oil-free pressure gauge. It also has a highly accurate flow meter with a flow rate that ranges from 0.5 to 15 SCF/hour. This product is made of brass so it has a very sturdy construction that was designed with longevity in mind. It’s compatible with CO2 controllers manufactured by this brand and any other 120V controllers or timers. This CO2 regulator comes with all the necessary tools and it’s easy to set up. You’ll also get two plastic tank washers and 12 ft of CO2 dispensing line.

What We Like Most

Heavy-duty solenoid valve

Oil-free pressure gauge

Made of brass

Compatible with 120V controllers or timers

Includes two washers and 12 ft of CO2 dispensing line

Our Synopsis:

This is a high-quality and long-lasting CO2 system with an extremely precise flow meter that will keep optimal carbon dioxide levels in your fish tank. It’s easy to set up, use, and adjust according to your needs.

Analyst Rating

10

U.P. Aqua CO2 Regulator

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This CO2 system is made of heavy brass to ensure durability and improve the product’s resistance to rust. It has dual gauges that are easy to read and an electronic solenoid complete with a high precision needle valve that enables accurate dosing of carbon dioxide. You can adjust the working pressure and you can pair it with 120V timers. You can also use it to manage multiple tanks. This CO2 regulator comes with all the necessary installation tools and you can set it up quickly. The solenoid doesn’t overheat and it provides a silent operation.

What We Like Most

Made of heavy brass

Dual gauges

Compatible with 120V timers

No overheating

Easy to install

Our Synopsis:

This CO2 regulator has a sturdy construction that was built to last. You can set it up easily and you can adjust the working pressure according to your preferences.

Analyst Rating

Buyer's Guide

The lack of carbon dioxide in your fish tank will inhibit your plants’ growth, but too much of this gas can cause excessive growth of algae and it can be toxic for your fish. To create an optimal environment for your fish and plants, you’ll need stable and consistent injections of carbon dioxide, which can be achieved by using CO2 regulators. There’s a wide selection of these devices available, and trying to find the one that suits your needs can be overwhelming. There are certain factors to consider when searching for a CO2 regulator, including their ease of use, readability, and accessories they come with.

Easy Setup and Use

You’ll want to find a product that’s easy to set up, and for the majority of CO2 regulators, the installation process is quite straightforward and it comes down to simply turning a couple of knobs and connecting several tubes. However, you’ll want to find a product that’s also easy to use and doesn’t require excessive adjustment to be able to function properly. While some fine tuning will be necessary whichever product you choose, you’ll still want this process to be as hassle-free as possible.

Type of Materials

CO2 regulators should be built of strong and durable materials that can withstand high pressure and resist rusting, such as brass, steel or aluminum alloy. Some CO2 systems are constructed using improved sealing materials so that they can handle high temperatures and reduce the risk of leakage. CO2 regulators should be worthy investments, so it’s essential to find high-quality and long-lasting products.

Readability and Accuracy of the Gauges

CO2 regulators come with dual gauges, which are used to measure high and low pressure. If you’re a beginner in using CO2 regulators, it’s extremely important to be able to read and understand them, as this can help you notice any irregularities and react quickly. Gauges should display accurate measurements and they should be easy to read. If you have trouble reading small fonts, it’s best to choose a CO2 system with fonts that are large enough so that you can see everything clearly.

Type of Regulation

CO2 systems can perform single, dual, and sometimes even triple regulation. As the amount of CO2 starts to drop in the cylinder, the output pressure begins to increase and it can cause fluctuations in the amount of carbon dioxide that gets released in the tank. A CO2 system with a single-stage regulation reduces the output pressure once, while the one with a dual regulation reduces the pressure twice, so it provides more control over the amount of CO2 that ends up in a tank. For this reason, dual-stage regulators are a safer option, but that doesn’t mean that single-stage regulators aren’t reliable, they will just need more supervision. If you choose a single-stage regulator, it’s best to refill the cylinder as soon as you notice it’s running empty to avoid any pressure issues.

Accessories

When buying a CO2 regulator, pay attention to the items that are included in its kit. In addition to gauges, a quality CO2 regulator should come with a solenoid valve, a needle valve, a bubble counter, and a check valve. Solenoid Valve Your plants only need CO2 during the photosynthesis process, which happens only during daylight, so at night, any release of carbon dioxide would be wasted. A solenoid valve prevents this wastage by allowing you to connect the regulator with a programmed timer that automatically turns on and off the release of CO2 so that you wouldn’t have to do it manually. Some solenoid valves also come with a light that indicates when the timer is on or off, which makes things even easier. Needle Valve Needle valve, or a pressure relief valve is an essential part of a CO2 regulator kit because it allows you to control the rate at which CO2 enters your tank. You can fine tune the pace at which CO2 bubbles get released according to your preferences, and maintain a steady flow rate. Bubble Counter Bubble counter is a visual tool that helps you measure the number of bubbles that are pushed into your tank per second. This item isn’t always included in CO2 regulator kits, but it’s still useful to have as it can help you make further adjustments to the flow rate. Check Valve Check valve is an important item to have in your CO2 system for safety reasons. It prevents the water from re-entering the regulator, which could break it. Many bubble counters come with a built-in check valve to ensure that the water doesn’t reach the regulator.

ow to determine the amount of CO2 in your tank?

CO2 is naturally produced during the fish respiration process and it’s also a by-product of the plant decay, so it’s already present in your tank. The optimal amount your fish tank needs will depend on several factors, including the tank’s capacity, the number of fish and plants you have, as well as the type of plants and how much light they require. Plants that require high amounts of light grow faster, which means they need higher CO2 levels, as opposed to low-light plants, which grow at a slower rate and don’t require high amounts of carbon dioxide. That said, you can always incorporate a CO2 regulator to stimulate healthy living conditions, the difference is only in the amount of CO2 that’s needed. Another thing to bear in mind is how many fish you own. The more fish you have in the tank, the higher amounts of oxygen they need and the more waste they produce, which will result in additional CO2 production. If you add even more CO2, it may lower the immunity of your fish as well as cause gasping and suffocation. The quickest and easiest way to determine how much CO2 your tank needs is to use a drop checker. It contains a solution so that when it’s placed inside the tank, CO2 will leak into the drop checker and change the color of the solution. If the solution turns blue, you need more CO2 in your tank, and if it turns yellow, there is too much CO2 present. If it turns green, you have optimal CO2 levels and there’s no need for any additions.

How to set up a CO2 regulator?

CO2 regulators come with all the tools you need to install it, so you should be able to set it up quickly by following a few easy steps. Step 1: Connect the CO2 regulator to a cartridge First, you should attach your CO2 regulator with a cartridge. Majority of CO2 systems are compatible with the cartridges that are available on the market, so it’s unlikely you’ll need additional tools. Nonetheless, always check the compatibility of the product before you buy it just in case it requires a connector. Step 2: Connect the regulator to the air outlet and a diffuser The next step is connecting your regulator to the air outlet via a CO2 carrier tubing that comes with the product. You’ll need to link the bubble counter with the air outlet and then connect a diffuser to the end of the regulator. A diffuser converts carbon dioxide into bubbles that get released in the water. Some CO2 systems come with bubble counters included, but there’s no need to worry if your doesn’t, you can buy a bubble counter separately and add it to the regulator. Step 3: Place the diffuser in the wanted position The role of a diffuser is to distribute bubbles in the water, so keep this in mind when choosing how to position it. It’s best to put it in the area with the highest level of water circulation. Step 4: Place a drop checker in your tank As we’ve mentioned before, a drop checker will help you determine the amount of CO2 you have in your tank. Put the drop checker in your tank using a suction container. After you see the results, modify the flow rate accordingly. Typically, a flow rate that ranges from 1 to 3 bubbles per second should provide optimal readings in tanks that can hold up to 50 gallons.

How to read CO2 regulator gauges?

The gauge on the right is the high pressure gauge and it indicates how much CO2 is left in your regulator. The gauge on the right is the low pressure gauge and it shows how much carbon dioxide is being delivered to your solenoid and needle valve. It’s also known as the delivery pressure or working pressure. Generally, the gauge that measures high pressure should read a minimum of 1000 psi, while the gauge for low pressure should read at least 15-30 psi, and a maximum of 200 psi.

What pressure should a full CO2 regulator read?

A full CO2 tank should display the internal pressure that ranges from 800 psi to 850 psi, so if the pressure drops to around 750 psi, it means that the tank needs a refill. You shouldn’t allow the pressure to go as low as 500 psi, as this could cause excessive release of CO2 all at once, which is also known as the “end of tank dump” and it may be fatal for your fish.

Expert tip

It’s best to turn on your CO2 regulator 1 hour before the lights go on as it allows the carbon dioxide to build up, so that the plants can make use of it immediately as the lights turn on. Also, you can turn it off 1 hour before the lights go off, as there will still be enough CO2 in the water for the plants to benefit from it.

Did you know

CO2 reduces the pH levels of the water, so high amounts of it may be suitable for fish that prefer acidic, soft water conditions. Conversely, fish that prefer hard, faster-moving water may not cope so well with high CO2 levels.

Conclusion

Carbon dioxide is a natural ingredient of every fish tank, but you’ll need to determine what amount is optimal for your aquarium. After reviewing the options above, you should have a clearer picture of what kind of product will suit your needs. Whichever option you choose, make sure that it promotes safe and healthy living conditions for your fish and plants.