Free UK Shipping
On Orders £30+. Next Day on Orders £80+
Same Day Dispatch
Weekday Orders Placed Before 3pm
Free Returns
100% Satisfaction Guaranteed
Lifetime Support
With Extended Warranties
Free UK Shipping
On Orders £30+. Next Day on Orders £80+
Same Day Dispatch
Weekday Orders Placed Before 3pm
Lifetime Support
With Extended Warranties

Aquarium CO2 Systems

Give Your Aquarium Plants the CO2 They Need to Grow and Flourish

View Our Range
of CO2 Systems

Click Here to View

Consistently Receive Good Feedback

Our Customers Rate Us

4.8 / 5

Based on 4,092 Customer Reviews.
Providing Excellent Customer Service for 10 Years.

How a CO2 System Will Give You Better Plant Growth in Your Aquarium

If you constantly need to re-stock your aquarium plants because they either die, become overgrown with algae or generally have poor health then you're not alone. It's a problem that every person owning an aquarium has faced at one time or another. But how is it that people are able to create scenes like this...

Aquarium CO2 System shown in a planted tank

...and yet your plants seem to die a few weeks after you planted them? They must be doing something different, right? Correct! Let's look at exactly what they're doing and how you can replicate those results in your own aquarium.

No CO2 = No Photosynthesis = Dead Plants

Diagram of Photosythesis with and without CO2.

"Photosynthesis" - we all learnt about it in school didn't we? No doubt you know this already, but just to refresh, here's a definition of Photosynthesis:

"Photosynthesis is a chemical process through which plants produce glucose and oxygen from carbon dioxide and water, using only light as a source of energy."

Essentially, what this means is without a source of Carbon Dioxide, your aquarium plants can't properly Photosynthesise to produce the sugars they need to survive. Or to put it another way: No CO2 = A Dead Plant.

But how do you give your aquarium plants CO2? Thankfully, it's not as difficult as you might think; just as you use an air pump to pump Oxygen into your aquarium, you can buy Aquarium CO2 Systems to pump Carbon Dioxide into your tank. We'll look into that more further on.

How CO2 Supermarket Can Help You

Since 2010 we have been supplying the world's aquascapers with everything they need to create their own beautiful planted aquarium. For your convenience, we supply pre-bundled CO2 Systems for diffusing CO2 in your aquarium water.

Our Aquarium CO2 Systems Comprise Of

  1. Easy CO2 Adapter (optional)
  2. Gas CO2 Regulator
  3. Bubble Counter
  4. CO2 Diffuser
  5. CO2 Drop Checker
  6. High-grade CO2-resistant tubing
Let's explore the role of each of these parts

Easy CO2 Adapter

Photo of a SodaStream adapter sold in CO2 Systems from CO2 Supermarket. Photo of a SodaStream adapter in use.

One problem you may encounter while operating your CO2 system is actually sourcing the CO2 cylinders needed for your system. Our range of CO2 systems come with an (optional) adapter that enable you to use a range of easily accessible CO2 cylinders as your CO2 source. These include: SodaStream cylinders, Disposable Welding CO2 cylinders, or Paintball CO2 cylinders - simply select which type you'd like.

By using one of these adapters you are assured that a supply of CO2 is always conveniently available from a high street shop. Our CO2 Systems are customisable to enable you to select which adapter you would like to use.

Gas Regulator

Photo of a gas regulator contained in a CO2 System from CO2 Supermarket.

A gas regulator is needed to 'regulate' the high pressure from the CO2 cylinder to a lower, usable pressure for use in the aquarium. Our range of regulators are purpose-built for aquarium use and very safe, easy to install, and use.

The regulators included in our Aquarium CO2 Systems come with an integrated solenoid magnetic valve, which enable use of a timer plug to turn the CO2 off when the lights in your aquarium are switched off and the plants are not Photosynthesising.

Bubble Counter

Photo of a bubble counter attached to a co2 regulator.

A bubble counter is a simple but effective piece of equipment that enables you to monitor the dosing of CO2 into your aquarium. By counting the number of bubbles flowing through the unit, you can adjust the flow controller on the regulator to achieve the 'bubble count' you require.

For example, for a 150L aquarium a bubble rate of 60 bubbles / minute is a good starting point.

The bubble counters that we sell also include an integrated 'check valve' (aka 'one-way valve') that will prevent water from siphoning down the tubing from the aquarium and into your regulator, possibly causing damage.

CO2 Diffuser

Photo of a CO2 diffuser.

Going back to our school days again, in Science lessons we learnt that the rate of a reaction can be increased by increasing the surface area of the reactant, e.g. turning a solid block into a powder. The same principle applies to diffusing the CO2 in your aquarium water; the more surface area the CO2 has in contact with the water, the better the level of diffusion you will achieve. The way to do that is produce very small bubbles of CO2, rather than one large bubble.

The part responsible for this is the 'CO2 Diffuser'. The diffuser emits very small bubbles of CO2. The smaller the bubble, the more surface area, and the better the level of diffusion achieved.

We stock a wide range of diffusers, but the type included in our CO2 systems are known as 'atomizer' diffusers. Atomizer diffusers, as the name suggests, produce incredibly small bubbles of CO2, and therefore achieve very high levels of diffusion.

CO2 Drop Checker

Photo of a CO2 drop checker kit.

A drop checker is deployed within the aquarium and changes colour to reflect the level of CO2 in the aquarium water; yellow indicates too much CO2, blue indicates low CO2 levels, green indicates correct CO2 levels. This eliminates any guesswork as it enables the correct level of CO2 dosing for a specific aquarium. Adjustments can be made using the flow controller on the regulator, and using the bubble counter to monitor the dosing level.

The solution for the drop checker comes pre-mixed, so set-up and installation is done in just a couple of minutes.

CO2-Resistant Tubing

Photo of co2-resistant polyurethane tubing.

To connect your pieces of equipment together you will need to use tubing. It is not recommended to use the same PVC or Silicon tubing used for an air pump because it will react with the CO2 and will eventually crack or become porous, resulting in a leak. Instead we supply high-grade CO2-resistant Polyurethane tubing, which will not react with CO2.

Our Commitment to Customer Service

Over the years we have helped thousands of people successfully install and operate their CO2 system and create the beautiful planted tank they'd always dreamed of. All of our equipment comes with in-depth installation instructions, and we're always on-hand to provide assistance if needed.


Most Popular

Customer Reviews

Average Rating

Individual Reviews

Will B. Verified Buyer 26th Nov 2021
Great kit easy to set up Great kit easy to set up Nano Aquarium CO2 System for Planted Tank 20L - 100L
John W. Verified Buyer 26th Nov 2021
Does the job and saves a lot of agro with sourcing the old style co2 canisters for homebrew Does the job and saves a lot of agro with sourcing the old style co2 canisters for homebrew SodaStream Hambleton Bard S30 Adapter Injector
Michael M. Verified Buyer 23rd Nov 2021
Quick service,reasonable price and working well. Quick service,reasonable price and working well. CO2 Solenoid Valve for Planted Aquariums
Howard D. Verified Buyer 21st Nov 2021
Very friendly and helpful advice before I purchased the dual stage regulator kit.. well made, up and running quickly with excellent instructions... Noticed a difference after just a few days Very friendly and helpful advice before I purchased the dual stage regulator kit.. well made, up and running quickly with excellent instructions... Noticed a difference after just a few days Ultimate-SE Dual Stage CO2 System for Planted Aquarium Tank 20L - 500L+
Rob B. Verified Buyer 21st Nov 2021
Good quality products that arrived promptly. The system has been set up for over 3 weeks now and the plants are growing well with the bonus of no sign of algae. Queries were dealt with promptly by email, so overall, I'm very pleased. Good quality products that arrived promptly. The system has been set up for over 3 weeks now and the plants are growing well with the bonus of no sign of algae. Queries were dealt with promptly by email, so overall, I'm very pleased. Ultimate-Pro Dual Stage CO2 System for Planted Aquarium Tank 20L - 500L+
Cory M. Verified Buyer 17th Nov 2021
Really good co2 system, I like it a lot and getting a lot more growth since using it Really good co2 system, I like it a lot and getting a lot more growth since using it Pro Aquarium CO2 System for Planted Tank 20L - 500L+
Thomas P. Verified Buyer 17th Nov 2021
Works really well and easily bypasses the booby-trapped / anti-fill valves on SodaStream cylinders. Great service from co2 supermarket too, thank you! Works really well and easily bypasses the booby-trapped / anti-fill valves on SodaStream cylinders. Great service from co2 supermarket too, thank you! SodaStream Cylinder Refilling Adapter
Fabrizio Verified Buyer 13th Nov 2021
Excellent service, excellent quality merchandise Excellent service, excellent quality merchandise Complete Nano CO2 Drop Checker Kit
Jason M. Verified Buyer 12th Nov 2021
Great Product! Easily fills even the boobytrap versions of the sodastream cannister. I had some initial teething problems filling using a 1.5kg co2 cannister - it just refused to fill. I ended up wasting the whole 1.5kg cannister attempting to fill the sodastreams. I decided to order a larger co2 donor, 6.5kg this filled the sodastreams great. I think it was to do with the amount of pressure the read more... Great Product! Easily fills even the boobytrap versions of the sodastream cannister. I had some initial teething problems filling using a 1.5kg co2 cannister - it just refused to fill. I ended up wasting the whole 1.5kg cannister attempting to fill the sodastreams. I decided to order a larger co2 donor, 6.5kg this filled the sodastreams great. I think it was to do with the amount of pressure the 1.5kg was outputting, it just was not enough! So my advice is make sure you get a large donor cylinder. SodaStream Cylinder Refilling Adapter


Small logo for CO2 Supermarket
Reply from CO2 Supermarket
Thank you for your review, Jason. Most likely is that the first donor cylinder wasn't expelling liquid CO2. For refilling purposes it's important to request a cylinder with a dip/siphon tube so that liquid CO2 is expelled from the cylinder, otherwise the SodaStream cylinder won't refill.

Jonathan . Verified Buyer 12th Nov 2021
Spot on. Many thanks Spot on. Many thanks SodaStream Connection Hose (DIN 477 - UK / Europe)
See more reviews  Loading
Cart Activity

Someone added a product to their cart

View Product

Someone added a product to their cart

View Product