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8 Best Aquarium CO2 Regulators of 2021 – Reviews & Top Picks

Nicole Cosgrove

Aquarium CO2 Regulator with 12 DC Solenoid-Big Dual GaugeIf you are in the market for a new aquarium CO2 regulator, you may find that you have a lot of questions about some of the different features offered as well as brands available. There is quite a large selection to choose from, and the best one is not always apparent.

We have chosen eight of the most common CO2 regulators used for aquariums so you can see the biggest differences between them. We’ve also included a buyer’s guide where we break down the aquarium CO2 regulator to see what the critical components are.

Join us while we take an in-depth look at aquarium CO2 regulators and discuss gauges, adjustability, durability, bubble counters, and more to help you make an educated purchase.

A Quick Glance at the Winners of 2021

Image Product Details
Best Overall
Winner
FZONE Aquarium CO2 Regulator FZONE Aquarium CO2 Regulator
  • Dual gauges
  • Updated solenoid
  • Precise control
  • Best Value
    Second place
    VIVOSUN Hydroponics CO2 Regulator VIVOSUN Hydroponics CO2 Regulator
  • Durable brass components
  • 0-4000 PSI
  • Includes plastic tubing
  • Premium Choice
    Third place
    AQUATEK CO2 Regulator AQUATEK CO2 Regulator
  • Precision needle adjustment
  • Dual gauge
  • Cool-touch solenoid
  • Titan Controls CO2 Regulator Titan Controls CO2 Regulator
  • Brass components
  • Precision flow meter
  • Heavy-duty solenoid valve
  • Manatee Co2 Regulator Manatee Co2 Regulator
  • Two gauges
  • Stainless steel construction
  • Bubble counter
  • The 8 Best Aquarium CO2 Regulators

    1. FZONE Aquarium CO2 Regulator – Best Overall

    FZONE Aquarium CO2 Regulator

    The FZONE Aquarium CO2 Regulator is our pick for the best overall CO2 regulator. This model features two gauges. One lets you read the pressure of the inner tank while the other measures the outgoing pressure. The updated solenoid uses direct current for reduced noise, and less power prevent overheating. The precise control mechanism allows for accurate CO2 regulation. It includes the check valve as well as all necessary tools for fast, easy installation.

    We found the FZONE Aquarium CO2 Regulator to be precise and quiet. There was no humming and our aquatic plant looked great. The only negative thing we can report is that the gauges are quite small, and you might have some difficulty reading them if you have bad eyes.

    Pros
    • Dual gauges
    • Updated solenoid
    • Precise control
    • Check valve and tools included
    Cons
    • Gauges are small

    2. VIVOSUN Hydroponics CO2 Regulator – Best Value

    VIVOSUN Hydroponics CO2 Regulator

    The VIVOSUN Hydroponics CO2 Regulator is our pick for the best aquarium CO2 regulator for the money. This brand uses all high-quality brass components for long-lasting durability. It includes all required tubing, and the regulator gauge reads from 0-400 PSI, which should be suitable for almost every situation. The industrial-grade solenoid ensures a long-lasting regulator with a wide range of applications.

    We found this brand attractive and functional, and the low cost makes it hard to pass up. The adjustment valve is our only complaint because it is extremely sensitive, and the useful range for aquariums is small and can be challenging to set perfectly.

    Pros
    • Durable brass components
    • 0-4000 PSI
    • Includes plastic tubing
    Cons
    • Sensitive adjustment

    3. AQUATEK CO2 Regulator – Premium Choice

    AQUATEK CO2 Regulator Mini

    The AQUATEK CO2 Regulator is our premium choice aquarium CO2 regulator. This model has two gauges for reading pressure inside the tank as well as pressure leaving. Precision needle adjustment allows for extremely accurate adjustments. The cool-touch solenoid does not get hot, and it’s also very quiet while running. This model is also one of the few multipurpose CO2 regulators on this list, and it can even attach directly to a paintball gun.

    We found the AQUATEK CO2 Regulator constructed very well and adjustment dials and gauges look and feel high-quality and professional grade. The only trouble we had was getting it adjusted perfectly with the extremely sensitive controls. The bubble counter and check valve included with this regulator also do not match up to the same quality.

    Pros
    • Precision needle adjustment
    • Dual gauge
    • Cool-touch solenoid
    • Multipurpose
    Cons
    • Difficult to adjust
    • Bubble counter and check valve

    4. Titan Controls CO2 Regulator

    Titan Controls HGC702710 CO2 Regulator

    The Titan Controls HGC702710 CO2 Regulator features all brass components for durability as well as reliability. The precision flow meter helps you know exactly what the CO2 pressure is always, and the heavy-duty solenoid valve will last years without needing replacement. It also makes very little noise while it operates.

    What we didn’t like about the Titan Controls HGC702710 CO2 Regulator was that we had two, and both arrived in damaged packaging, and in one case, the packaging damaged one on the hoses.

    Pros
    • Brass components
    • Precision flow meter
    • Heavy-duty solenoid valve
    Cons
    • Poor packaging

    5. Manatee Co2 Regulator

    OKSLO CO2 Regulator Aquarium

    The Manatee Co2 Regulator features attractive stainless steel in its construction. It’s durable and resists corrosion and features two gauges to help you keep informed of the CO2 pressure within the tank as well as outgoing gas. The bubble counter works as well as our top choices and is a strong selling point.

    The downside of the Manatee Co2 Regulator is that it is quite expensive and heavy compared to many others. The solenoid is quite loud while it’s operating, and you can hear it a good distance away. It also gets quite warm to the touch.

    Pros
    • Two gauges
    • Stainless steel construction
    • Bubble counter
    Cons
    • Expensive
    • Solenoid gets hot
    • Noisy

    6. DoubleSun Aquarium CO2 Regulator

    DoubleSun

    The DoubleSun Aquarium CO2 Regulator is easy to install, and the needle output valve allows you to adjust the output rate from 30 – 60 PSI. It uses a DC solenoid, which means no hum while the regulator is in operation and less power required. The solenoid will stay cool to the touch, so there is little chance of overheating. The high-precision fine-tuning valve helps you set the right amount of CO2 that enters your tank water.

    Unfortunately, if you have bad eyes, you may find the meters on the DoubleSun Aquarium CO2 Regulator a little difficult to read, and we found the fine-tuning valve to be too sensitive to set easily. We were also disappointed that there is no bubble counter included with this model.

    Pros
    • Dual Meters
    • DC solenoid
    • High precision fine-tuning valve
    Cons
    • Small meters
    • Difficult to set right
    • No bubble counters

    7. YaeTek Aquarium CO2 Regulator

    YaeTek Aquarium CO2 Regulator

    The YaeTek Aquarium CO2 Regulator features two mini gauges to help you keep an eye on the pressure inside and leaving your tank. It’s available in four colors gold, silver, red, and blue. There is also a bubble counter included to help you see how much CO2 is entering your aquarium.

    There were a few downsides to the YaeTek Aquarium CO2 Regulator. The gauges are extremely small and challenging to read without getting very close to them. There are also no instructions telling you how to use the regulator, so if you are new to adding CO2 to your aquarium, you may need to seek another model or outside help.

    Pros
    • Two gauges
    • Available in four colors
    • Bubble counter
    Cons
    • Tiny gauges
    • Poor instruction
    • Noisy

    8. ZRDR CO2 Regulator Aquarium

    ZRDR CO2 Regulator Aquarium

    The ZRDR CO2 Regulator Aquarium is another brand that features a dual gauge readout to keep an eye on your CO2 levels. It also has a DC solenoid that runs cooler, uses less power, and is much quieter than the brands that use AC solenoids. The construction feels sturdy and durable.

    We had high expectations for the YaeTek Aquarium CO2 Regulator. However, we were unable to get an even flow rate using it. We would set it, and after a few minutes, we would notice the bubble count had changed. It’s too unpredictable to operate unattended.

    Pros
    • Dual Gauge
    • DC solenoid
    • High precision
    • Durable
    Cons
    • Flow doesn’t stay even

    Buyer’s Guide

    If you have an aquarium that contains live plant life, you are going to need to add carbon dioxide to the water to nourish the plants and keep them healthy and growing. However, if you add too much CO2 to the water, you will risk killing your fish. You may notice your fish look drunk if there is too much carbon dioxide in the water.

    To achieve and maintain the correct level of CO2 in your aquarium, you need a CO2 regulator. The regulator is a simple device that stands between your CO2 tank and your aquarium. It usually has one or more meters on it to let you know how much CO2 remains, and there can be other components as well, including a bubble counter.

    Let’s discuss the critical parts of the aquarium CO2 regulator in this section.

    Safety

    The carbon dioxide is extremely cold as it leaves the pressurized canister and can cause immediate damage to your skin, so never open an unregulated valve.

    While adding CO2 to your aquarium is not usually considered to be dangerous, there are some safety measures you should take to make sure there is no danger. We recommend performing the soapy water test on all equipment regularly to make sure no CO2 is escaping into the air. The gas is not dangerous, but if there is a lot of it in a small place, it can push out the oxygen. Low oxygen levels are especially hazardous in small, enclosed spaces, and rooms.

    Soapy Water Test

    To perform the soapy water test, mix one-teaspoon dish soap with one-cup water. Use a small paintbrush to paint the water over the connections and hoses. If bubbles appear as you are painting, you have a leak that needs repair.

    Drop Checker

    The drop checker is not part of the aquarium CO2 regulator. It is a device that helps you determine the correct amount of CO2 to add to your water. The right amount can vary quite a bit depending on how many plants you intend to grow, the size of your tank, how much light reaches the water, how much the water moves around and how many fish you have.

    The drop checker is a device that attaches to your aquarium. Inside the device is a fluid that changes color based on the carbon dioxide present in the air. In most cases, blue means you need to add more, while yellow means cut back. You aim to keep the color green by adjusting the flow accordingly.

    Durability

    The first thing you are likely to notice about your aquarium CO2 regulator is the quality of the material it uses. Higher quality bands tend to be brass and stainless steel, and you also want to look at the hoses, washers, and meters to look for quality construction.

    Make sure there are no bent or malformed hoses because these can wear out prematurely.

    Ease of Use

    There are two parts to being easy to use. It must be easy to install and contain all the correct size fittings. Connect ability is usually not an issue, but with internet sales, it’s a lot easier to purchase a model from a country that uses a different measuring system.

    The second part of being easy to use refers to how easy it is to get the exact amount of CO2 flowing into your tank. Many models feature extremely sensitive controls that are hard to put where you want them. In our review, we tried to point out any models that were challenging to achieve the desired flow.

    Gauges

    Your aquarium co2 regulator usually has one or two gauges on them. If there is only one, it is telling you how much CO2 remains in the tank. If there are two, the second is telling you the pressure that is going into your aquarium.

    We’ve found these gauges to be fairly accurate across brands, and the main concern is if it’s large enough to read easily. Many of these gauges are very small, and we often need to make tiny adjustments and a small, hard to read gauge will make these adjustments difficult.

    Needle Valve

    Needle valves are also commonly called pressure relief valves, and they allow precise control over the amount of CO2 entering your aquarium. With these valves, you can adjust the bubbles per second.

    Needle valves can also help protect you from an excessive CO2 that can sometimes occur as the tank is getting low, and the pressure diminishes.

    Bubble Counter

    The bubble counter is an added part of some models that allows you to see how much CO2 is entering your tank by counting the bubbles in the chamber. We highly recommend bubble counters because they lead to increased precision, but they do not always need to come as part of the regulator, it’s possible to purchase them separately.

    fish in aquarium
    Image Credit: PxHere

    Solenoid

    Having an electrical solenoid on your regulator is required to automate the CO2 delivery system. An automated system is preferable to a manual one because it is more consistent and can guarantee more even levels of CO2 over time.

    AC Solenoid

    There are two types of solenoids AC and DC. AC solenoids use alternating current directly from your wall. These devices will be less expensive and less complex, but they can make a considerable amount of hum and tend to get very warm, which can lead to overheating and malfunction.  They also use more power, which, while small, can add up over time.

    DC Solenoid

    DC solenoids use direct current either by converting electricity in your home or by using a battery. These devices can cost more money, but they are very efficient and run quiet and cool. The primary downside to these solenoids is that it’s often hard o tell when the battery needs replacing ahead of time.

    Check Valve

    The check valve is a critical component that may not come with your regulator. If it didn’t, you would need to purchase a check valve separately. Its primary function is to prevent water from the aquarium from getting into the regulator. If water gets into the regulator valve, you will need to purchase a new one.

    Tubing

    The tubing is not usually too high on the priorities list, and you can find it easily in most pet stores if your model does not come with the required amount. The only concern when buying tubing is that it is for carrying CO2 as many common types of tubing is not.

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    Conclusion

    When choosing a new aquarium CO2 regulator, we recommend something like our top choice. The FZONE Aquarium CO2 Regulator has two easy to read gauges, a DC solenoid and comes with a check valve. It’s easy to set up and maintain. If you are on a budget, our best value. The VIVOSUN Hydroponics CO2 Regulator is a perfect choice and will help you maintain a healthy living environment in your aquarium. It’s nor as fancy as the top model, but it has precision controls and is extremely consistent.

    We hope that you have enjoyed reading over this in-depth look at aquarium CO2 regulators and found it helpful and informative. If you have learned something new, please share these aquarium CO2 regulators on Facebook and Twitter.

    For more Aquarium gear reviews, check out these posts:

    Nicole Cosgrove

    Nicole is the proud mom of Baby, a Burmese cat and Rosa, a New Zealand Huntaway. A Canadian expat, Nicole now lives on a lush forest property with her Kiwi husband in New Zealand. She has a strong love for all animals of all shapes and sizes (and particularly loves a good interspecies friendship) and wants to share her animal knowledge and other experts' knowledge with pet lovers across the globe.