Best CO2 Diffuser and Reactor

best CO2 reactor

Sera Flore CO2 Reactor 500

The Sera Flore CO2 Reactor is the best CO2 diffuser and reactor for those looking for a premium budget friendly device. This CO2 reactor can handle 66-160 gallon tanks and dissolves CO2 very efficiently. It performs at 500 to 1000 bubbles per minutes.


If you have plants in your aquarium, you should know to add extra carbon dioxide into the mix. This is because for the most part, aquariums can’t naturally support the carbon dioxide demands of most plants. As you already know, plants absorb carbon dioxide and release oxygen as a byproduct. This oxygen is absorbed by the fish in your aquarium and produce carbon dioxide as waste. Unless your aquarium is loaded with fish, you need to find a way to produce that extra carbon dioxide. Keep in mind most aquariums with plants need anywhere between 15 to 30 ppm of CO2 to thrive.

This is where the CO2 diffuser comes into play. A CO2 diffuser or reactor is usually part of a CO2 regulation system that includes a CO2 regulator, a CO2 cylinder, and a CO2 diffuser. The CO2 cylinder is the source of the CO2, and the CO2 regulator allows you to control the flow of the gas from the cylinder to the diffuser. Finally, the CO2 diffuser will break up a steady stream of carbon dioxide into tiny bubbles that dissolve into the fish tank more easily and efficiently.

Getting the best CO2 diffuser is really a function of your aquarium and budget. The cheapest CO2 diffuser is an airstone. However, they are quite inefficient and make big bubbles. There is also the ceramic glass CO2 diffuser, which makes finer bubbles and secured to the aquarium glass. Then you have the ladder CO2 diffuser, which is generally used in smaller tanks and shaped like a ladder. Next, there are in-line CO2 diffusers, which work well in larger aquariums and are considered safe and effective. There are also CO2 atomizers, which can diffuse CO2 in atomize stage and produce better results.

Finally, you have the CO2 reactor, which is usually more expensive but gives you a very high output of CO2. And unlike normal CO2 diffusers, CO2 reactors do not directly release carbon dioxide into the aquarium. Instead, the water and CO2 are mixed separately in a contained reactor and then released back into the tank.

Best CO2 Diffuser and Reactor

Sera Flore CO2 Reactor 500

best CO2 reactor

If you want the best CO2 reactor that is by far the best way to inject co2 into your tank, the Sera Flore is the way to go. This CO2 reactor is towards the higher end of the budget CO2 diffusers and certainly gets the job done. It is built with top performance and dissolves CO2 very easily. The company reports performance in the 500 to 1000 CO2 bubbles per minute, which is more than enough for most situations.

After testing it out a bit, we can confirm this claim. It works much more efficiently and is more reliable than most of the ceramic diffusers we tried and does a great job dissolving almost all CO2. Also, it is pretty quiet, but no completely silent. We did not find it annoying at all in a silent room.

Finally, installation is quite easy and it comes with all of the necessary parts. You also get suction cups and hose connectors with fasteners. Overall, the Sera Flore CO2 Reactor 500 is a very durable unit made of acrylic. It is fit for small tanks from 66-160 gallons. However, they also have a variety of sizes to choose from. This is definitely our top pick when you consider cost and value.

– Premium CO2 reactor
– 500-1000 CO2 bubbles per minute
– Relatively noise free
– Durable

Shop now at Amazon

Jardli Pollen Glass CO2 Diffuser, 50-75 Gallons

best co2 diffuser

The Jardli Pollen Glass CO2 Diffuser is the best CO2 diffuser on the market if you are looking for a premium ceramic model. This gadget allows for very efficient CO2 atomization through its ceramic membrane. The company advertises very high efficiency and dissolves up to 98% of the CO2 running through it. The bubbles create from this device are pretty fine and allows for optimal absorption by water plants.
This co2 diffuser is compatible with all CO2 tanks that have a 2 to 5 bubble per second injection rate. The ceramic membrane itself is around 2 inches in diameter and is enough for most 50 to 75 gallon tanks. If you need a smaller membrane, Jardli also sells the 1.5 inch version, which should cover 20 to 50 gallon tanks. Additionally, it comes with a nice U shaped glass connecting tube that avoids all blockage of CO2 flow. And of course you get two suction cups to mount the entire unit on the glass.

Compared to other ceramic co2 diffusers on the market, we think this one is clearly top shelf. The bubbles are small and efficient. The glass is nice and overall build quality is great. Jardli has been around in the business for a while now and is a name that we thoroughly trust.

– Premium Ceramic model
– For 50-75 gallon tanks
– U shaped glass connecting tube
– 2 suction cups for mounting

Shop now at Amazon

Aqua Medic CO2 Reactor 1000

best co2 reactor

If you have a giant plant tank, the aqua medic co2 reactor 1000 maybe the best co2 reactor for you. While this unit is way for expensive than your normal garden variety co2 diffuser, you get every penny of what you pay for. First and foremost, this thing can supply CO2 for tanks up to 500 gallons. That’s more than 10 times the amount that cheap CO2 diffusers can handle.

Next, the Aqua Medic is an extremely powerful unit that efficiently dissolves CO2 bubbles in any sort of current. We think it runs at least 50% better than standard CO2 diffusers and is a much better way to dissolve CO2. It is a fully enclosed hermetically sealed reactor that is mounted outside the aquarium or inside the cabinet. So it mixes the CO2 and water inside first and then pumps out the mixed product into your tank.

Please keep in mind that this is not your everyday CO2 diffuser. It is really for large setups and you will likely need a connect to a return line of a canister filter or a dedicated pump. The setup is complicated and the unit accepts all half inch tubing. However, if you have any sizable live plant system, this is the only way to go.

– Top end model
– Supports up to 500 gallons
– Runs 50% better than most diffusers
– Expensive

Shop now at Amazon

Jardli Glass Inline CO2 Atomizer

best inline CO2 atomizer

For those looking to attach inline to your canister outflow, the Jardli Glass CO2 Atomizer is the way to go. The advantage of an inline co2 diffuser system is that it basically makes your plant tank look way more beautiful. There are way less moving parts and less equipment to worry about, which also gives more space for your plants and fish. You can mount this unit to the outside or inside of your tank as long as you connect it to the outflow tubing of the canister filter.

The immediate benefits of this CO2 atomizer is that it creates a very fine mist of CO2 compared to traditional diffusers. The fine mist is great for plant absorption and growth and is achieved through enhanced CO2 dissolution via turbulent mixing inside the unit. Additionally, the inline mounting and active flow helps reduce the unnecessary build of of algae and bacteria around the diffuser disc.

Overall, the setup is quite simple. We highly recommend you draw CO2 from a pressurized source, which is not included in this unit. The input and output ports will connect to a 5/8 inch diameter tubing. If you need a different fitting, there is also the 13mm model for 1/2 inch diameter hoses.

– Great inline glass CO2 atomizer
– Less moving parts
– No algae buildup
– Setup is simple

Shop now at Amazon

Gulfstream Tropical CO2 Reactor

best CO2 reactor

If you want a simple and cheap CO2 reactor, the Gulfstream Tropical CO2 reactor is a great solution. Keep in mind that it is not a CO2 diffuser, so no ceramic plates or anything like that. It dissolves CO2 efficient by breaking down CO2 bubbles and mixing them with water inside the reactor. This also allows the unit to be install both inside and outside your plant tank.

It can handle about 70 gallons of water and you really shouldn’t go more than that. Sure it is a nice and cheap unit, but the clear trade offs come in terms of build quality. The entire unit definitely feels cheap and subpar compared to some of the glass CO2 atomizers we tried. We did not experience this, but there are some reports from others of leaking after using it briefly. If you know about these risks and are on a budget, we say give this unit a go.

– Nice and cheap CO2 reactor
– Dissolves CO2 efficiently enough
– Poor build quality
– Could end up leaking

Shop now at Amazon


Web Analytics