Chihiros Letkut 19/25 mm -CO2 diffuusori External XL

The diffuser is installed on the pressure side of the external filter. Filtered water passes through its body while CO₂ is forced through the ceramic element and broken into extremely fine bubbles.

The filter flow transports the mist through the return hose and distributes CO₂-rich water throughout the aquarium. The external configuration improves the appearance of planted layouts by keeping conventional glass diffusers and suction cups outside the display.

Key features

• External inline CO₂ diffuser
• XL model for 19/25 mm filter hose
• Installed in the external-filter return line
• Ceramic diffusion element
• Produces an ultra-fine CO₂ mist
• Supports efficient gas dissolution
• Uses the external-filter water flow
• Reduces visible equipment inside the aquarium
• Suitable for large planted aquariums
• Suitable for high-flow external filters
• Aluminium, acrylic and ceramic construction
• Transparent inspection section
• Replaceable ceramic element
• Minimum working pressure approximately 1.5 bar
• Requires a pressurised CO₂ system
• Diameter approximately 30 mm
• Height approximately 136 mm

Technical information

• Product: Chihiros External CO₂ Diffuser XL
• Type: external inline CO₂ diffuser
• Intended use: pressurised CO₂ fertilisation
• Installation: external-filter return hose
• Model size: XL
• Hose size: 19/25 mm
• Nominal connection: approximately 20 mm
• Materials: aluminium, acrylic and ceramic
• Diffusion element: ceramic
• Replaceable element: yes
• Recommended minimum working pressure: approximately 1.5 bar
• Diameter: approximately 30 mm
• Height: approximately 136 mm
• Integrated pressure control: no
• Integrated check valve: no
• Intended water type: freshwater planted aquariums

Installation

1. Confirm that the external filter uses 19/25 mm hose.
2. Disconnect the filter and all inline electrical devices.
3. Close the external-filter valves.
4. Install the diffuser in the return hose.
5. Follow the indicated water-flow direction.
6. Push the hoses fully onto the connectors.
7. Secure the hoses with suitable clamps when required.
8. Support the hose installation to prevent strain.
9. Connect pressure-resistant CO₂ tubing.
10. Install a separate check valve.
11. Fill the filter circuit and start the external filter.
12. Remove trapped air and check for water leaks.
13. Start CO₂ injection at a low setting.
14. Adjust working pressure and bubble rate gradually.
15. Monitor aquarium pH, the CO₂ indicator and livestock.
16. Recheck all connections during the first day.