How to Set Up Aquarium Tubing and Air Diffusers
By Pro Shrimp | Published: 2026-10-20
Category: How-to Guides
Learn how to connect aquarium airline tubing, install a non-return valve, and set up air diffusers like air stones or flexible bubble walls for better aeration.
Quick answer
To set up aquarium tubing and air diffusers, attach the airline from your air pump to a non-return valve, then run the tubing to your chosen diffuser (air stone or flexible diffuser) and secure it in the tank. Always install the valve between the pump and the diffuser to prevent water back-siphoning.
Why the non-return valve matters
A non-return valve is a small one-way check valve that sits in your airline tubing. Its job is simple: it lets air flow from the pump to the diffuser but blocks water from traveling back up the tube if the pump stops or loses power. Without it, water can siphon back through the airline, draining your tank and flooding your pump—potentially ruining both. This is especially important for setups where the diffuser sits below the water surface, which is almost always the case.
Choosing between air stones and flexible diffusers
Air stones and diffusers both create bubbles, but the bubble pattern and placement flexibility differ. Flat air stones like Betta Air Disks create a vertical column of fine bubbles and are easy to hide under substrate or decor. Flexible diffusers such as the Superfish Air Flexi-Diffuser can be bent around driftwood, rocks, or into corners to create a bubble wall or curtain. Your choice depends on whether you want a focused bubble column or a more spread-out effect along the tank's shape.
Step-by-step setup
- 1. Cut and connect the airline tubing: Measure the distance from your air pump to the tank. Cut a length of standard 4/6mm silicone or plastic airline tubing long enough to reach from the pump to the tank, plus a few extra inches for slack. Push one end onto the pump outlet nozzle. Use sharp scissors or a tubing cutter for a clean, square cut—jagged edges can cause leaks.
- 2. Install the non-return valve: Cut the tubing about halfway between the pump and the tank. Insert the non-return valve so the arrow on the valve points toward the diffuser (away from the pump). Push the tubing ends firmly onto both barbs of the valve. If you install the valve backward, no air will reach the diffuser. Double-check the arrow direction before sealing.
- 3. Attach the air diffuser: Push the free end of the tubing onto the inlet barb of your chosen diffuser. For Betta Air Disks, the connection is standard 4/6mm. For Superfish Air Flexi-Diffuser, the same size fits. Position the diffuser in the tank—lay a disk flat on the bottom or bend the flexible diffuser along a rock or the back wall. Air stones need to be fully submerged to work properly. If bubbles are very large or uneven, the stone may need cleaning or replacement.
- 4. Test the system: Plug in the air pump and watch the bubbles. Check for air leaks at each connection point—listen for hissing or look for bubbles escaping from tubing joints. If the pump runs but no bubbles appear, check the valve orientation and tubing seals. If bubbles are weak, the pump may be undersized for the depth or the diffuser may be clogged. Try a more porous stone or a stronger pump.
- 5. Secure and hide the tubing: Use suction cup clips or adhesive cable ties to run the airline along the tank rim or back wall. Keep tubing away from heater cords and filter intakes to avoid tangling or heat damage. Avoid sharp bends in the tubing—they restrict airflow and can cause the pump to overwork.
Products used in this guide
- Betta Airline Non-return Valve: Betta Airline Non-Return Valves are one-way protective valves to protect air pumps from water syphonning back through the airline. Failure to install one could mean loss of water from your aquarium and damage your air pump beyond repair. Installing this valve is the single most important step to prevent equipment damage and water loss during a power outage or pump failure.
Betta Airline Non-return Valve - Betta Air Disks: Betta Air Disks are flat air stones suitable for placing on the bottom of an aquarium or pond. They create a column of air bubbles to decorate, aerate and improve water circulation. Their flat shape makes them easy to hide under rocks or plants, providing aeration without being an eyesore.
Betta Air Disks - Superfish Air Flexi-Diffuser: Superfish Air Flexi-Diffuser can be bent around driftwood, stones or in corners, providing air bubbles wherever you want in the aquarium. Available in three sizes: 12.5cm, 30cm and 60cm. Flexible design lets you create bubble walls or curves that follow your hardscape, adding both oxygen and visual interest.
