5-Pack Aquarium Air Pump Check Valve – One-Way Anti-Backflow

5-Pack Aquarium Air Pump One-Way Check Valve

Keep your fish tank equipment safe and running smoothly with these one-way non-return check valves. Designed for standard aquarium air tubing, this set of 5 plastic check valves prevents water from flowing back through the air line when your pump shuts off — protecting your pump and other connected equipment from water damage.

Why You Need These Check Valves

Whether your air pump is mounted above or below the waterline, backflow is a real risk every time the pump powers down. These compact inline valves act as a one-way gate: air flows freely toward the tank, but water cannot travel back toward the pump. Simply insert one valve per air line outlet and enjoy peace of mind.

Key Features

• Anti-backflow protection: One-way design ensures air flows in only one direction — into the tank.
• Universal fit: Compatible with standard aquarium air tubing with an inner diameter of approximately 4 mm (0.16 in).
• Flexible placement: Allows your air pump to be positioned above or below the water surface without backflow risk.
• Durable plastic construction: Lightweight, corrosion-resistant, and built for long-term aquarium use.
• Value pack: Comes with 5 valves — enough for multiple outlets or tanks.
• Easy installation: Simply slide each end onto your air tubing. The "OUT" side faces the tank; the opposite side is the air inlet.

Specifications

• Quantity: 5 pcs per bag
• Overall Length: 36 mm / 1.42 in
• Middle Circle Diameter: 8 mm / 0.31 in
• Inner Diameter (each end): 3 mm / 0.12 in
• Outer Diameter (each end): 4 mm / 0.16 in
• Suitable For: Standard air tubing with ~4 mm inner diameter
• Material: Plastic
• Made in China

What's in the Box

• 5 × One-Way Non-Return Check Valve

Note: Please allow 1–3 mm variance due to manual measurement. Screen color settings may cause slight differences from the actual product color.

You May Also Like

• Dog & Cat Cooling Mat – Ice Silk Pet Bed S to 2XL
• Kitty Kurlz Accordion Cat Scratcher Toy with Bell Balls
• 100 PCS Plant Support Clips for Orchid, Flower & Vine Stems

Learn more: U.S. Fish and Wildlife Service

Frequently Asked Questions

Q: How do I know which end of the check valve faces the fish tank?

A: The valve is labelled — the side marked "OUT" is the air outlet and should face toward your aquarium. The opposite end is the air inlet and connects to the tubing coming from your air pump.

Q: Will these check valves fit my existing aquarium air tubing?

A: Yes — these one-way valves are designed for standard aquarium air tubing with an inner diameter of approximately 4 mm (0.16 in), which is the most common size used in fish tanks. Please verify your tubing diameter before purchasing.

Q: How many check valves do I need for my air pump?

A: You need one check valve per outlet. For example, a dual-outlet air pump requires two check valves. This 5-pack gives you enough for multiple setups or spares for future use.