Different Types of CO₂ Diffusers
There are several diffuser types suited for different aquariums:
- Ceramic diffuser: popular and economical, produces fine visible CO₂ bubbles.
- External reactor: often coupled to the filter, dissolves CO₂ efficiently without visible bubbles.
- Inline diffuser: integrated on the external filter tubing, combines discretion and performance.
Optimal Positioning in the Aquarium
For optimal diffusion:
- Place the diffuser near the filter outlet so bubbles are carried by the current.
- Avoid dead spots or poorly circulated areas, otherwise CO₂ won’t distribute evenly.
- Use a small circulator or powerhead if necessary to homogenize diffusion.
How to Adjust the CO₂ Flow Rate?
The flow rate should match the tank size and number of plants:
- Bubble counter: allows precise adjustment (e.g., 1 to 3 bubbles/sec for 100L).
- Permanent test (drop checker): changes color depending on CO₂ level in water (ideally green).
- pH/KH: monitor these parameters to avoid excesses that could stress fish.
Automate Diffusion with a Solenoid Valve
To avoid wasting CO₂ at night (when plants don’t photosynthesize), use a programmable solenoid valve:
- It automatically stops CO₂ injection at night.
- It activates with the lighting, for a more natural and economical effect.
Mistakes to Avoid
- Diffusing too close to the substrate: CO₂ will rise without dissolving.
- Excessive water flow: can expel CO₂ from the water too quickly.
- No control testing: risky for fish health.
In summary: to properly diffuse CO₂, combine the right equipment, correct positioning, and regular dosing. This ensures healthy plants and a balanced aquarium.