Hose Alphacool 5–9 mm, flexible coolant tubing for custom liquid cooling (Alphacool 68007)

Alphacool flexible coolant hose with a 5 mm inner diameter and 9 mm outer diameter is designed for custom liquid cooling loops in PCs and other electronics. The tubing provides a pliable, kink-resistant connection between radiators, pumps, reservoirs and water blocks. Compatible with standard compression fittings for 5/9 mm tubing, this hose is intended for coolant transport in closed-loop systems and for creating neat, curved runs where rigid pipe would be impractical.

Advantages

The hose combines flexibility and dimensional stability, allowing smooth routing through tight spaces while maintaining a secure seal with compression fittings. Its inner and outer diameters match common small-bore cooling components, reducing the need for adapters. The material resists common coolants and provides consistent flow characteristics, minimizing the risk of restriction or turbulence at connection points.

Suitable for

• Custom PC liquid cooling loops with 5/9 mm compression fittings
• Connections between pumps, radiators, reservoirs and water blocks
• Retrofitting or replacing existing small-bore coolant lines
• Compact builds and tight-routing installations

Key specifications

• Inner diameter: 5 mm
• Outer diameter: 9 mm
• Flexible, kink-resistant tubing suitable for coolant transport
• Compatible with standard compression fittings for 5/9 mm hoses
• Designed for use with liquid coolants in PC and electronics cooling systems

How to use

Cut the hose to the required length with a sharp tube cutter to ensure square ends, then push it onto the barbed section or into the compression fitting until seated evenly. Secure fittings according to the manufacturer's instructions to maintain a leak-free connection. Route the tubing to avoid sharp bends that could restrict flow; allow gentle curves and use support clips or cable ties as needed to prevent strain on fittings. Fill and bleed the cooling loop following standard liquid cooling procedures before operation.

Usage recommendations

Inspect hose ends and fittings for secure seating and test the system at low power to confirm there are no leaks. Use coolants recommended for PC liquid cooling and perform regular maintenance checks to prevent deposits or discoloration that may affect flow. Replace the tubing if signs of hardening, cracking or persistent discoloration appear.