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Free UK Shipping
On Orders £20+. Next Day on Orders £80+
Same Day Dispatch
Weekday Orders Placed Before 3pm
10 Year Warranty
With Lifetime Help & Support

Aquarium CO2 Systems

The Aquarium CO2 System Specialists who give you Free Shipping*, Free Returns & Free Expert Advice

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Providing Excellent Customer Service for 6 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.

Your Aquarium is a Closed Ecosystem

The most important aspect you need to consider is that you are creating an artificial world for your plants and fish, encased within glass or plastic. What that means is the nutrients and elements that your plants need don't occur as they do in the wild, and just as you feed your fish to satisfy their needs, your plants also need to have their needs satisfied too.

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.

Nutrients & Elements

Any plant, whether aquatic or terrestrial, needs a variety of nutrients to grow and maintain a good state of health. In the wild these nutrients are provided by natural means but because an aquarium is a closed ecosystem those nutrients must be supplemented to maintain strong growth and good health. If those nutrients aren't supplemented the plant will eventually die, or certainly have a lacklustre appearance.

Plants require nutrients at different rates and volume, some are required at higher volumes, such as Potassium (K), Phosphorus (P), and Nitrogen (N) - these are known as 'Macronutrients'. Other nutrients are also required, but at lower amounts or concentrations. These are know as 'Micronutrients' and include elements such as Boron (B), Copper (Cu), Iron (Fe), Manganese (Mn), Molybdenum (Mo) and Zinc (Zn).

But how do you go about sourcing those nutrients and elements? They sound more like things you'd find in a Science laboratory rather than a pet store. Well, just as with the CO2 aspect, we can help with this too.

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, and also complete aquarium fertiliser mixes that contain all of the required nutrients and elements to sustain vigorous plant growth in your aquarium.

Our Aquarium CO2 Systems Comprise Of

  1. Easy CO2 Adapter (optional)
  2. Gas 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 ensuring 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.

If you know you can source a supply of CO2 cylinders and an adapter won't be needed, then you can choose from our 'CO2 Systems without Adapters' range.

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 without problem. 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

Brett N. Verified Buyer 27th Apr 2017

Functions as advertised, can unscrew from a full 6...

Functions as advertised, can unscrew from a full 60bar Soda stream bottle without destroying the seal. Fats shipping. Functions as advertised, can unscrew from a full 60bar Soda stream bottle without destroying the seal. Fats shipping. Adapter for SodaStream Cylinders
Donato P. Verified Buyer 25th Apr 2017

Brilliant product and customer support from the ve...

Brilliant product and customer support from the very beginning! Brilliant product and customer support from the very beginning! Nano Aquarium CO2 System for Planted Tank 20L - 100L
Tim F. Verified Buyer 25th Apr 2017

Nice unit at a decent price. I like the needle val...

Nice unit at a decent price. I like the needle valve which gives me very tight control over the amount of CO2 entering my Calcium Reactor. Service was awesome. Nice unit at a decent price. I like the needle valve which gives me very tight control over the amount of CO2 entering my Calcium Reactor. Service was awesome. CO2 Regulator with Solenoid, Dual Gauges & Adjustable Output Pressure
Lee T. Verified Buyer 25th Apr 2017

Works perfectly, the tap is very sensitive, so it'...

Works perfectly, the tap is very sensitive, so it's perfect for getting the right amount of flow. Works perfectly, the tap is very sensitive, so it's perfect for getting the right amount of flow. CO2 Regulator with Single Pressure Gauge for Horizontal Cylinder Valves
Robert . Verified Buyer 23rd Apr 2017

Excellent Product, the shipping was fast, to Canad...

Excellent Product, the shipping was fast, to Canada over the long Easter weekend. I love the setup and its my first time using a Co2 system in my tank so I am not a prp at this and the provided instructions made for a very easy install. Will buy this a again if I get a second aquarium one day. Thumbs up guys!! Excellent Product, the shipping was fast, to Canada over the long Easter weekend. I love the setup and its my first time using a Co2 system in my tank so I am not a prp at this and the provided instructions made for a very easy install. Will buy this a again if I get a second aquarium one day. Thumbs up guys!! Advanced Aquarium CO2 System with Adapter for Planted Tank 80L - 500L
David B. Verified Buyer 21st Apr 2017

A very good product and excellent service from CO2...

A very good product and excellent service from CO2 supermarket. Order arrived very promptly. Online instructions were clear and easy to follow. Set up makes a big difference to my tank. After four days the 12V transformer for the solenoid failed two days before I was to leave on holiday. Yet CO2 supermarket were able to respond to a panicked e-mail on a Sunday and supply a replacement before I read more... A very good product and excellent service from CO2 supermarket. Order arrived very promptly. Online instructions were clear and easy to follow. Set up makes a big difference to my tank. After four days the 12V transformer for the solenoid failed two days before I was to leave on holiday. Yet CO2 supermarket were able to respond to a panicked e-mail on a Sunday and supply a replacement before I left. Advanced Aquarium CO2 System with Adapter for Planted Tank 80L - 500L
David A. Verified Buyer 19th Apr 2017

My first attempt at adding CO2 to my tank, I am pl...

My first attempt at adding CO2 to my tank, I am pleased with the set up using Sodastream bottle, I found the kit easy to set up and the drop checker suggests the level of CO2 in the tank is correct (just over one bubble per second, 140 ltr tank). My plants are quite basic but seem in good health, O2 bubbles from leaves appear after 4 or 5 hrs, CO2 on for 8hrs, timed to be on 1hr before LED lighting read more... My first attempt at adding CO2 to my tank, I am pleased with the set up using Sodastream bottle, I found the kit easy to set up and the drop checker suggests the level of CO2 in the tank is correct (just over one bubble per second, 140 ltr tank). My plants are quite basic but seem in good health, O2 bubbles from leaves appear after 4 or 5 hrs, CO2 on for 8hrs, timed to be on 1hr before LED lighting for 7-8hrs Advanced Aquarium CO2 System with Adapter for Planted Tank 80L - 500L
James F. Verified Buyer 18th Apr 2017

Works perfectly and fast delivery. Recommended

Works perfectly and fast delivery. Recommended Works perfectly and fast delivery. Recommended Advanced Aquarium CO2 System with Adapter for Planted Tank 80L - 500L
Hannes G. Verified Buyer 17th Apr 2017

funktioniert perfekt

funktioniert perfekt funktioniert perfekt Adapter for SodaStream Cylinders
Paul Verified Buyer 16th Apr 2017

Drop checker came broken. Seal on regulater split ...

Drop checker came broken. Seal on regulater split after a week cheap tat save money buy better Drop checker came broken. Seal on regulater split after a week cheap tat save money buy better Advanced Aquarium CO2 System with Adapter for Planted Tank 80L - 500L


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Reply from CO2 Supermarket
I'm sorry to hear you've had a problem, Paul. From time to time problems do inevitably occur, but if you had let us know then we would be more than happy to assist and overcome whatever problem you're having. It's unfortunate you chose to leave a negative review rather than contact us and provide us with an opportunity to help you. Obviously, unless we're made aware of a problem then there is nothing we can do to fix it.

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