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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

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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

John B. Verified Buyer 21st Nov 2020
Fantastic quality very very well made. Works very well indeed. Just great cannot fault this product in any way. Fantastic quality very very well made. Works very well indeed. Just great cannot fault this product in any way. Advanced Adapter For Disposable CO2 Cylinders
Stephen B. Verified Buyer 11th Nov 2020
This has been amazing and already saved me money. Well worth the investment and CO2 Supermarket delivered quickly. The best option in the UK. This has been amazing and already saved me money. Well worth the investment and CO2 Supermarket delivered quickly. The best option in the UK. SodaStream Connection Hose (DIN 477 - UK / Europe)
Andy Verified Buyer 3rd Nov 2020
Better than the bottled stuff! Better than the bottled stuff! All-in-One Complete Macros and Micros Aquarium Plant Fertiliser
Nick P. Verified Buyer 26th Oct 2020
The drop checker is great, however, the solution that came with it appears bad, it is green straight out of the bottle rather than the blue it should be. The drop checker is great, however, the solution that came with it appears bad, it is green straight out of the bottle rather than the blue it should be. Complete Nano CO2 Drop Checker Kit


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Reply from CO2 Supermarket
This happens frequently and is because the solution reacts with the CO2 levels within the bottle. If you put it into the drop checker and leave it for a few hours you'll see it changes back to blue again.

Maxim K. Verified Buyer 23rd Oct 2020
It was quite easy to setup, although I was careful as it's my first CO2 setup. Seems to be working well so far with a sodastream adapter and a bottle! It was quite easy to setup, although I was careful as it's my first CO2 setup. Seems to be working well so far with a sodastream adapter and a bottle! Nano CO2 Regulator with Solenoid Magnetic Valve and Adjustable Output Pressure
Tomas R. Verified Buyer 22nd Oct 2020
Excellent co2 system with clear instructions. looking forward to finally getting my plants to grow! Excellent co2 system with clear instructions. looking forward to finally getting my plants to grow! Advanced Aquarium CO2 System for Planted Tank 80L - 500L
Nick P. Verified Buyer 22nd Oct 2020
I've had this a couple of weeks and it's working really well. The bubble rate and pressure have stayed exactly as I set, and the solenoid has worked flawlessly. I've had this a couple of weeks and it's working really well. The bubble rate and pressure have stayed exactly as I set, and the solenoid has worked flawlessly. CO2 Regulator with Solenoid, Dual Gauges & Adjustable Output Pressure
Colin R. Verified Buyer 18th Oct 2020
Still setting up but seems ok Still setting up but seems ok Mixer Reactor CO2 Diffuser - Regular for Aquariums up to 150L
Denis H. Verified Buyer 15th Oct 2020
Just the item needed to complete my set up. Just the item needed to complete my set up. Advanced Adapter for SodaStream Cylinders
Louis C. Verified Buyer 15th Oct 2020
Perfect. Easy and fast filling. Perfect. Easy and fast filling. Replacement SodaStream Valve
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