Description:
A check valve is a small but critically important piece of equipment for any aquarium running an air pump. Without one, if your air pump loses power, water can siphon back through the airline tubing and into the pump, causing water damage or flooding. A check valve prevents this by allowing air to flow in one direction only, from the pump to the tank, while blocking any reverse flow of water.
This is particularly important if your air pump sits below the waterline of your tank, where the risk of backflow is highest. Even if your pump sits above the waterline, a check valve is inexpensive insurance against the unexpected, and something we recommend to every customer running an air pump.
Check valves are simple to install. Cut your airline tubing and insert the valve in line between your air pump and your air stone or sponge filter, making sure the arrow on the valve points toward the tank. Compatible with standard 4mm airline tubing. Pack of 12, giving you enough for multiple tanks or setups across a fish room.
These valves come in a convenient bulk pack of 12, making them perfect for multi-tank setups. It gives you plenty of spares whether you are plumbing a single aquarium or running lines across an entire fish room with multiple punps or a large multiple outlet pump.
If you're running a Pet Worx Single or Twin Air Pump, or any other air pump pairing it with a check valve is strongly recommended.
Manufactured by Petworx, an Australian company established in 1980.
Suitable for freshwater and marine aquariums.
Product Features:
- Prevents back-siphoning of water into your air pump during power loss or system failure
- One-way airflow design allows air to pass into the aquarium while blocking reverse water flow
- Helps protect air pumps from water damage and extends equipment lifespan
- Essential safety component for any aquarium running an air pump system
- Highly recommended for setups where the air pump sits below the aquarium waterline
- Simple inline installation between air pump and airline accessories
- Clear directional arrow ensures correct installation and reliable operation
- Compatible with standard 4mm aquarium airline tubing
- Ideal for multi-tank fish room setups and individual aquariums
- Suitable for freshwater and marine aquariums
Product Specifications:
- Type: Aquarium Air Check Valve (Non-Return Valve)
- Function: One-way airflow protection
- Compatibility: Standard 4mm Aquarium Airline Tubing
- Installation: Inline between air pump and air-driven equipment
- Brand: Pet Worx (Established 1980)
- Pack Size: 12 Pack
- Suitable For: Freshwater and Marine Aquariums
Items Included:
- 12 x Pet Worx Aquarium Non-Return Check Valves
Pet Worx - Check Valve - 12 Pack
Pet Worx - Check Valve - 12 Pack
Low stock: 5 left
Everything about shipping, specifications and warranties is just below.
Why Shop With Us — Our Guarantee & Shipping Info
Why Shop With Us — Our Guarantee & Shipping Info
✅ Quality Products - Reliable aquarium supplies for your setup.
🚚 Standard Shipping ($11.95 - $19.95) - Safe & reliable delivery, arrives within 3-10 business days. Shipping cost: $11.95 small orders, $14.95 medium orders, $16.95 large orders, $19.95 bulk orders.
🛡️ Warranty Support - Most eligible equipment and accessories are backed by a 1-year manufacturer warranty, with claims handled through us.
🔄 Easy Returns - Most unopened dry goods can be returned within 14 days for change of mind, subject to our return conditions.
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Tips Before You Buy — Product Guidance
Tips Before You Buy — Product Guidance
💡 Unsure which product is right for your tank? Visit our Education section or Blogs for help choosing the best equipment.
🐟 Beginners can start with: How to set up your aquarium, while everyone can check out Aquarium Maintenance & Care for ongoing tank tips!
🌿 Not all products are suitable for every tank size - Double-check dimensions and specifications before purchasing.
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How This Check Valve Compares
🛡️ Pet Worx Aquarium Check Valve
- 💧Prevents Back-Siphoning: Allows air to travel toward the aquarium while blocking water from travelling back through the airline if the pump stops.
- 🔌Protects Your Air Pump: Helps prevent water from reaching the pump during power outages, accidental disconnection, or other interruptions to airflow.
- ⚙️Simple Inline Installation: Easily installs between your air pump and air-driven equipment using standard aquarium airline tubing.
- ↔️Clear Flow Direction: The directional arrow makes it easy to identify the correct installation orientation.
- 🐟Useful Across Multiple Setups: The 12-pack provides check valves for multiple tanks, spare equipment, or future aquarium setups.
⚠️ Air Pump Without a Check Valve
- 💧Backflow Risk: If the pump stops and the conditions allow siphoning, water can travel backwards through the airline toward the pump.
- ⚡Greater Equipment Risk: Water reaching an air pump can cause damage and may result in equipment failure.
- 🔧No Automatic Protection: The airline system itself provides no dedicated barrier against reverse water flow.
- 📍Position Dependent: The risk of back-siphoning is particularly important when the air pump is positioned below the aquarium waterline.
- 💰Avoidable Risk: A small, inexpensive component can provide an additional layer of protection for your air pump and aquarium setup.
We mention check valves in the descriptions of our air pumps and air stones for good reason. It's one of the cheapest accessories in the store and one of the most important. A flooded power board or a damaged air pump from a single power outage costs far more than a pack of check valves. The 12-pack makes it practical for fish room keepers and breeders running multiple air-driven setups.
Check valves are low maintenance but should be inspected periodically. If you notice reduced airflow from your air pump, a blocked or stuck check valve is a common cause. Replace if the valve no longer allows free airflow in the correct direction or shows signs of cracking or deterioration. With a 12-pack on hand, replacements are always ready when needed.
Frequently Asked Questions
What does a check valve actually do?
It allows air to flow in one direction only, from your air pump into the aquarium, and prevents water from flowing back down the airline. Without one, a power outage or pressure drop can cause water to siphon back into your pump, potentially damaging it or causing leaks.
Do I need one if my pump sits above the waterline?
Yes, it is still strongly recommended. Even when positioned above the waterline, unexpected power loss or pressure changes can still cause backflow. A check valve is cheap protection against expensive damage.
How do I install it?
Simply cut your airline tubing and insert the check valve inline between your air pump and your air stone or sponge filter. Make sure the arrow on the valve points toward the aquarium (direction of airflow). That’s all it takes.
How do I know if a check valve has failed?
If airflow drops significantly or stops, a stuck or blocked valve is often the cause. Remove the valve temporarily to test airflow. If performance returns, replace the valve. With a 12 pack, you will always have spares ready to go.
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