A CO2 system’s main purpose is to inject and dissolve CO2(carbon dioxide) gas into the planted aquarium water in a controlled manner.
3 MAIN PARTS
A complete CO2 system for planted aquarium has 3 main parts and includes a number of useful accessories.
This is one area where it is better to spend on quality parts, than to solve issues arising from using cheaper quality parts later on (problems such as leaking tanks or inaccurate tuning of CO2 injection rates). Being cheap on this aspect can costs more in the long run
CYLINDER
This is the metal container that stores Carbon dioxide in compressed form.
REGULATOR
Regulator (with solenoid) – This device releases CO2 gas in a controlled manner from the cylinder.
The CO2 gas is injected into a CO2 diffusion device (3). The solenoid connects to a power outlet; the regulator releases CO2 when power is supplied to the solenoid.
This allows us to control the timing of CO2 injection by turning off/on the power supply. (usually done using a power timer). Flow rate of CO2 gas released is controlled by a needle valve.
DIFFUSER
CO2 diffusion device – This mixes CO2 gas with tank water. It can be an in-tank diffuser/atomizer (CO2 line from regulator feeds to device inside the tank itself), or inline-diffuser/atomizer or CO2 reactor (CO2 line from regulator feeds into device that attaches to filer outflow).
I recommend using a reactor (most efficient) or inline atomizer (both are installed along the filter outflow line) to reduce equipment in the tank itself.
OTHER COMPONENTS
- CO2 TUBING: This connects the CO2 line from the regulator to the other parts
- Bubble counter – This is fitted before the diffuser/reactor and after the check valve as a visual guide to how much CO2 is bubbling into the tank
- One-way check valve – This is fitted between the regulator and bubble counter to prevent back flow of water into the regulator. Many bubble counters already come with in-built check-valves.
- Diffuser/reactor/atomizer – one of these devices (some are in-tank while others attach to the filter outflow) is necessary to diffuse CO2 into the tank water
POINTERS
some tips and tricks
QUALITY GOES THE DISTANCE
A quality CO2 injection system from GLA costs around $300 USD (including tank, regulator with attached solenoid).
Choose either a reactor or inline atomizer for CO2 dissolution. Remember that reactors depend on a certain flow rate to function optimally. Read more here on the differences bON A BUDGET between the 2 in natureaquarium.org
ON A BUDGET?
A Fire Extinguisher Cylinder or beverage setup can work for smaller planted aquariums. Search for used tanks also can work but check the hydro date on them first.
The aquatek premium regulator is popular among the budget crowd but is not as reliable.