CO2 Setup – Basic Guide

As highlighted by my earlier post on Co2, having sufficient Co2 is important for most planted tank. That’s why I’ve decided to share a basic guide on Co2 setup.

Importance of Co2 (once again)

Carbon dioxide plays a vital role in the health and management of your aquascape – no matter which aquascape style you decide to create.

As one of the key components in photosynthesis, carbon dioxide is essential to the growth and stability of the plant life in your aquarium.

In a natural setting, aquatic plants would ingest most of their CO2 through the substrate provided by mud or decaying plants in their area.

In an aquarium, the level of CO2 is much lower because the substrate imitates a natural landscape and there are fewer decaying plants in the area.

This imbalance often leads to problems with the health of your plants and, as a result, many aquascapers have found great success in supplementing their aquariums with additional CO2 to assist their plant life to grow stably in the aquarium.

The process of setting up this CO2 injector requires many different moving pieces; however, the long-term benefits are quite clear in creating a much healthier and stable aquascape.

Co2 in aquarium

Required Tools and Pieces for Co2 Setup

There are numerous tools and pieces required for a proper c02 setup. Below is a brief list and description of the required equipment.

CO2 Bottle

Carbon dioxide comes in numerous sizes, similar to how a propane tank is sized for a grill or camp stove.

The larger the bottle, the more CO2 it will contain and, in general, purchasing wholesale will assist you with the long term cost.


The regulator acts as the injection tool which releases pressure from the bottle to a lower and more manageable output.

Usually, regulators will come with a gauge that allows you to monitor the rate of injection and make appropriate changes based on your requirements.


Solenoids act as a system automation tool that will disable the injection of your CO2 based on a timer.

This brings value to your CO2 system because it allows the aquarium to be more self-sufficient.

For example, when you’re away from home and unable to turn off the CO2 injector, the solenoid will disable the injection for you.

Bubble Counter

The bubble counter is a metric tool that allows you to quantify the CO2 that has been pushed into your aquarium.

This equipment is usually added to your filter, which then measures the rate of bubbles exported per second.

If necessary, you can use the bubble counter to determine if your aquarium requires more or less CO2.


The diffuser is the tool that inserts the CO2 into your aquarium.

Typically, the diffuser is a porous material that injects CO2 into the tank through a fine mist of bubbles.

The diffuser’s main purpose is to equally disperse the CO2 gas throughout your aquarium water so that it is more effectively absorbed by the entire aquascape.


Tubing acts as the connector between your regulator and diffuser.

While fairly straightforward, one aspect to keep in mind is to use tubing that is CO2 tolerant.

Tubing is often not used for the same purpose, so be sure to choose one with the correct properties.

Drop Checker

The drop checker is a color-coded gauge that measures the concentration of CO2 in your aquarium water.

As opposed to the regulator or bubble counter that measure the rate of injection, the drop checker gives clear insight into the CO2 saturation in your aquarium.

This is a key component in the system as it provides insight on the health of the actual tank.

Too much CO2 is usually considered to be unhealthy for your fish, whereas too little will not facilitate plant development.

Use a drop checker to understand where your aquarium falls in that spectrum.

co2 setup

Management and Implementation

Generally, there are two approaches to the implementation of a CO2 injection system – DIY system and Pressurized system.

DIY System

There is a “do-it-yourself” method, which involves mixing water, sugar, and yeast in a sealed container and connecting it to your aquarium through a series of tubes and self-made regulators.

This approach, while cost effective, is not recommended for larger tanks; the DIY method would eventually be unsustainable, especially in larger tanks.

Check out this youtube video if you are interested to create a diy co2 system:

Pressurized System

Moving to a pressurized system is more common amongst larger tanks of 40 gallons or more.

The pressurized system also holds more opportunity for key metric observation and automation through the Solenoid tool.

Recommended Co2 System:

In conclusion

The implementation and management of your CO2 system is unique to the requirements of your aquarium, however it is of vital importance to also consider the other elements your aquarium requires such as light and fertilization.

Finding a balance between each of these aspects is the key to a successful and healthy aquascape. Good luck!

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