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If you ask any of the aqua hobbyists, they will tell you one of the most important factor for a successful planted aquarium, is the injection of CO2. 

In planted aquarium, CO2 is often the limiting factor. With higher CO2 level, aquarium plants flourish and grow. Without sufficient CO2 level, plants are unable to utilize the necessary nutrients, and instead allow algae to grow.

Pressurized CO2 System is the best and most effective way for introducing CO2 into your aquarium.

Equipment for pressurized CO2 system can often looks complicated to a beginner hobbyist. Today, we like to break down the installation to few simple steps   

What is commonly found in pressurized  CO2 system?



 CO2 cylinder

 Storage of CO2

 CO2 regulator

 Regulate the speed of CO2 release

 CO2 Bubble counter

 Allow user to calculate the speed of CO2 release

 CO2 check valve

 Prevent aquarium water to flow into the CO2 cylinder

 CO2 tubing

 Connect the regulator to the diffuser

 CO2 diffuser

 Create CO2 micro bubbles in aquarium, allow more CO2 to dissolve in water

We will use our ANS Professional CO2 System to demonstrate the setup. In the later part, we will give more details and properties for each items used.

CO2 Cylinder

CO2 cylinders basically store your CO2! It usually comes in aluminum or alloy steel material. Aluminum cylinders are lighter and have better appearance and are more expensive. Alloy Steel cylinders are durable and cheaper!  

ANS Alloy Steel CO2 Cylinder is durable and able to withstand high pressurizes CO2. Built in with safety mechanism that prevent any sudden leakage of CO2.

Come in 2L, 3L and 5 Liter cylinder. Choose your cylinder capacity well. Usually, a 2L will last about 4-5 months for a 60 Liter aquarium. You will not like to travel more often than necessary just to get your CO2 Cylinder refill!

CO2 Regulator

CO2 regulator regulates the speed of CO2 release. There are 2 types of regulator (manual/automatic). We usually recommend user to use automatic regulator.

Manual regulator (picture below) has 1 pressure gauges.

Manual regulator is cheaper, no frills regulator.  It allows CO2 to be controlled and release from the cylinder. However, the CO2 release can be unstable and it will be hard to adjust the amount of CO2 release. It is because manual regulator relies on CO2 cylinder pressure. As CO2 in cylinder gets lesser, CO2 pressure in cylinder decreases, hence affecting the amount of CO2 release. So if you leave your manual regulator on running, you will find the speed of CO2 injection getting slower over time, even if there is CO2 in the cylinder.

Automatic regulator (picture below) has 2 pressure gauges.

ANS CO2 Regulator w/ Solenoid

One measures the capacity of CO2 stored in the CO2 cylinder. The other measures the output pressure, output pressure gauge provide constant amount of CO2 release regardless of the capacity of CO2 in the cylinder.

ANS CO2 Regulator with solenoid is a 3 in 1 regulator
1. Creates a constant output pressure of 50-60PSI. 
2. A fine tune adjuster that allow user to adjust amount of CO2 release accurately and precisely.
3. Integrated solenoid control!

What is the use of solenoid?

Plants need CO2 when light is on and CO2 injection is unnecessary when light is off. Solenoid is use to turn on and off CO2 by simply switching on and off the electrical supply.

Electricity ON = CO2 injection

Electricity OFF = CO2 supply cut off!

Some will ask if they use regulator without the solenoid as they can manually turn the fine tune adjuster off at night and turn it on daily! However, from a season hobbyist, most will tell you this daily ritual can be very tiring. It will be easier to control the CO2 by just a flip of a switch.  Furthermore, you can also connect ANS CO2 Regulator with solenoid to common electronic 24hr timer.  With this you can leave the system running for months without you touching it.  

Solenoid on a timer

Bubble Counter

Bubble counter is use to measure the amount of CO2 injected into your aquarium. It is important to know how much CO2 is injected to your aquarium as too much CO2 may suffocate your fishes and shrimp, while too little will stunned the growth of plants. As a guide, a fully planted aquarium should inject 1 bubble/second for every 30 – 45 liter of water. You can also get a CO2 Checker to check the amount of CO2 in your aquarium.

ANS Brass Bubble Counter is fabricated out of brass metal and thick glasses that can withstand high pressurize CO2 output without losing shape. It clear glass column allows easy counting of CO2 bubbles. It is also integrate with a brass check valve to prevent back-flow of water.

Check Valve (One Way Valve)

Check Valve prevents water from aquarium to flow back to your CO2 cylinder. It is important to have a check valve because if water enters the cylinder, it can cause rust in the interior of the cylinder and prevent proper CO2 refilling.

ANS Brass Check Valve is an excellent check valve that prevents no water flows back to your CO2 Cylinder even under high pressurize CO2 output.

CO2 Tube

There are many types of tube available. We do not use the same that we use with air pump.  The common air pipe will not be withstand the pressure needed for CO2 system and may leak CO2 after sometime.

ANS CO2 Resistant Tube is design to support high pressurize CO2 output and do not degrade over time.

CO2 Diffuser

CO2 Diffuser are use to diffuse CO2 efficiently into your aquarium. There are various types of diffuser available. 

ANS Opti Glass Diffuser Nano

ANS Opti Glass Diffuser Nano creates micro bubbles through a ceramic disc that effectively diffuse CO2 into the water. The more CO2 dissolved in water the more CO2 available for plants.  So it is important to have a diffuser rather than just a normal air stone. Opti glass material use in the diffuser gives elegant visual effect to your planted aquarium.

CO2 monitor device (Optional)

As all planted aquarium are different, the amount of CO2 intake by plants are different. To measure accurately if the amount of CO2 is enough, we use CO2 monitor device. CO2 monitor device accurately measure the amount of CO2 dissolved in the water. 

ANS Drop Checker measure accurately the amount of CO2 in the water. Opti glass material used enhances elegant visual effect to your planted aquarium.

Things to take note when using CO2 System:

  1. Do not place CO2 Cylinder under sun or hot area
  2. Do not place CO2 Cylinder at a damp area
  3. Use high grade check valve to prevent water from flowing back to the cylinder

ANS Professional CO2 System is a complete CO2 System. Come with everything needed for a CO2 system. Plug and play.

ANS Professional CO2 System includes:

  • ANS Alloy Cylinder 
  • ANS Co2 Regulator with Soleniod
  • ANS Brass Bubble Counter
  • ANS High Resistant CO2 Tube
  • ANS Opti Glass Diffuser Nano

ANS Professional CO2 System :

******* Join our EOA CO2 refill program *******

We do 1 to 1  exchange of CO2 cylinder when you purchase ANS Professional CO2 System from us. Ready immediately, no waiting required.

Next article The Essential Guide to the Nitrogen Cycle in Aquariums