TW Straight Joint (White Knob)

The TW Straight Joint (White Knob) provides aeration for your aquarium.

Key Features

• Increases dissolved oxygen levels for healthier fish
• Quiet operation for home and office aquariums
• Suitable for freshwater and marine setups

The TW straight joint with white knob for tuning airflow

A straight joint with a control knob does two jobs at once: it connects two lengths of airline and lets you dial the flow through that line. That is genuinely useful when one pump feeds several outlets and you want the air stone in a betta tank gentler than the one driving a sponge filter next door. The knob gives you fine adjustment without swapping pumps, so each tank gets the bubble rate that suits its livestock.

In Singapore’s warm tanks, balancing aeration across multiple setups is common, since oxygen is less abundant at 27-29C and over-driving a nano tank just stresses small fish. Set the knob to a steady, quiet stream, push the tubing firmly onto both barbs, and recheck the setting after a few days as it can drift. A check valve upstream is wise so water never siphons back during a power cut.

See more under air systems; for getting flow right, our air stone guide and oxygenation guide are helpful.