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Why do we need CO2 in the aquarium?

In a planted aquarium, CO2 is the one nutrient the water cannot supply on its own. Inject it steadily and plants pearl, colours deepen and algae loses its head start.

CO2 for beginners

Build your CO2 system

Seven questions about your aquarium, your cylinder and your filter, and you end with a system whose parts are made to fit each other. The price is the sum of the parts.

Build your system Or take a ready-made kit

CO2Artists

A growing family of the world's best aquascapers, all proud to put CO2Art equipment at the heart of their work.

Meet the artists

Tag your aquarium #co2artartist — every tile is the creator's own post, credited and linked.

Dual-stage regulators

Pro-SE or Pro-Elite?

Both are dual-stage, so the pressure does not surge when the cylinder runs low, the fault single-stage regulators are known for. The difference is how much pressure they give you, and how steadily they hold it.

PRO-SE Series - Aquarium CO2 Dual Stage Regulator with Integrated Solenoid

Pro-SE

1.259,00 kr

Max pressure
40 PSI2.7 bar
Holds pressure to within
about5 PSI
Best for
Most planted aquariums.
View product
New Pro-Elite Series V2 - The Most Advanced Aquarium Dual Stage CO2 Regulator

Pro-Elite V2

2.105,00 kr

Max pressure
80 PSI5.5 bar
Holds pressure to within
about1 PSI
Best for
Several aquariums off one cylinder, manifolds, and the steadiest bubble count.
View product

What aquascapers say

4.8/5

across 2,000+ reviews

Read all reviews
  • 50,000+aquascapers worldwide
  • 60+countries shipped to
  • 13+years of aquarium CO2

Great service, fast shipping and easy to set up. I got the full CO2 system and cannot be more happy!

Nadezda S.Verified buyer, Ireland

Best Regulator I ever had. Easy to handle and very good quality. Set it up together with a CO2 Inline diffuser and the Check valve from co2art. Highly recommend to use all these parts together.

Alex C.Verified buyer, Germany

That's a great device to help kick-off plants, works amazingly well with SodaStream adapter bought separately. My 110L is thriving after just one week with it.

Mohamed A.Verified buyer, Switzerland

Excellent! With very high atomization of CO2 it becomes very effective. Highly recommend it.

Håkan E.Verified buyer, Sweden

Very fast service, easy to install and you get the perfect size of bubbles, like dust!

George G.Verified buyer, Cyprus

Complete kits

Regulator, diffuser, tubing, drop checker and the small parts, made to fit each other. Pick by regulator and by diffuser.

Pro-SE Series Complete Aquarium CO2 System with in-tank Flux_ Diffuser Pro-SE with in-tank diffuserPRO-SE regulator + Bazooka Flux diffuser1.742,00 kr Pro-SE Series Complete Aquarium CO2 System with New Inline CO2 Diffuser Pro-SE with inline diffuserPRO-SE regulator + inline diffuser for the filter hose1.819,00 kr New Pro-Elite Series V2 Complete Aquarium CO2 System with in-tank Flux_ Diffuser Pro-Elite with in-tank diffuserPro-Elite V2 regulator + Bazooka Flux diffuser2.589,00 kr New Pro-Elite Series V2 Complete Aquarium CO2 System with New Inline CO2 Diffuser Pro-Elite with inline diffuserPro-Elite V2 regulator + inline diffuser for the filter hose2.665,00 kr

Prefer to choose part by part? Build your system.

Best sellers

The regulators, diffusers and drop checkers most aquascapers start with.

4.6

PRO-SE Series - Aquarium CO2 Dual Stage Regulator with Integrated Solenoid

1.259,00 kr
4.7

CO2Art Inline CO2 Aquarium Atomizer Diffuser System

From 366,00 kr
5.0
Save 20%

NEW IO Diffuser - Acrylic Series - In-Tank CO2 Diffuser

Sale priceFrom 153,00 krRegular price 191,00 kr
4.7

In-Tank Bazooka Flux_ CO2 Diffuser for Planted Aquariums

From 214,00 kr
4.2

New Pro-Series CO2 Adapter for Paintball - Sodastream - Disposable

214,00 kr
4.8

New Pro-Elite Series V2 - The Most Advanced Aquarium Dual Stage CO2 Regulator

2.105,00 kr

Instagram

Follow us on Instagram

Follow @co2art

Instagram post by @co2art @co2art CO2ArtFrom gentle droplets to thriving green, the essence of vibrant plant life is nurtured. Just as this moss flourishes, our Flux Diffuser delivers the CO2 your aquatic plants need to bloom. Create your own tranquil ecosystem. 🌿10 Sep 2026 Instagram post by @co2art @co2art CO2ArtJust as nature thrives with perfect balance, your planted tank needs precise CO2 delivery. These seals ensure consistent flow for lush, vibrant growth, much like the healthy, green moss thriving here. 🌱9 Sep 2026 Instagram post by @co2art @co2art CO2ArtThe serene mist and sun-kissed trees inspire. Our Pro-Elite Series V2 CO2 system brings this natural harmony to your aquarium, enabling truly vibrant plant life. 🌱8 Sep 2026 Instagram post by @co2art @co2art CO2ArtBathed in golden light, this scene reminds us of thriving ecosystems. Our NEW Precision Pro-Series Bubble Counter helps cultivate that same lush, vibrant growth in your planted tank. Pure natural beauty. ✨6 Sep 2026 Instagram post by @co2art @co2art CO2ArtDrawing inspiration from nature's untouched beauty. The silent work of quality essentials helps your aquatic plants bloom, creating a sanctuary as lush as these moss-covered stones. 💚4 Sep 2026 Instagram post by @co2art @co2art CO2ArtAdding substrate to an established tank can feel like asking for a cloudy water disaster. 😅4 Sep 2026 Instagram post by @co2art @co2art CO2ArtJust like the forest thrives under sunlight, your aquatic plants flourish with balanced CO2. Our Drop Checker Kit helps you maintain that perfect green, reflecting the lush moss beneath. Nurturing nature, inside and out. 🌿✨3 Sep 2026 Instagram post by @co2art @co2art CO2ArtThe secret to a beautifully balanced tank, with plants as lush as these, often lies in precision. Our Pro-Series Check Valve ensures flawless CO2 delivery, letting your aquatic garden blossom. Simple care for stunning results. 🌿2 Sep 2026
 

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