Air Line - Non Return/Check Valve - Protects Your Air Pump from Back-Siphoning
Best for: Anyone running an air pump and airstone in a reservoir who wants to stop water siphoning back and ruining the pump.
Our thoughts
A 99p part that can save you a £20-plus air pump. If your pump ever sits below the waterline of your reservoir, or loses power while the airline's still submerged, water can siphon straight back up the line and into the pump. This little valve stops that dead.
This is a simple non-return (check) valve that fits into your air line between the pump and the airstone. It contains a small internal mechanism that lets air flow through in one direction only, towards the airstone, and closes off if water tries to flow back the other way. "Back-siphoning" happens when a reservoir's water level sits higher than the pump, or when the pump loses power - without a check valve in place, water can travel back up the airline and flood the pump, which is a common way of killing an otherwise perfectly good pump.
Fitting one is genuinely a five-minute job: cut into the airline, push the valve in with the arrow pointing towards the airstone, and you're done.
How it compares
A standard, low-cost safeguard rather than a premium or branded component.
- Does the same job as the check valves bundled with air pumps from brands like Hailea and EcoPlus, just sold separately so you can fit as many as your system needs
- Cheaper than replacing an air pump that's taken on water through back-siphoning
- A basic mechanical part rather than anything with moving electronics to fail - simple by design
Not exciting, but genuinely cheap insurance against a fairly common and avoidable pump failure.
Usage guidance
Simple to fit, but position and orientation both matter.
Positioning
Fit the valve as close to the air pump as practical, and always keep the pump itself mounted above the highest water line in your system rather than relying on the valve alone.
Orientation
Check valves only work one way - fit it with the airflow direction pointing from the pump towards the airstone, not the other way round.
Multiple airlines
If you're running several airstones off one pump via a manifold, fit a check valve on each individual line rather than just the main feed.
Technical specifications
- Part type: Non-return / check valve
- Function: Allows airflow in one direction, blocks water flowing back towards the pump
- Fitting: Inline, fits standard airline tubing
- Use case: Fitted between air pump and airstone
- Recommended pairing: Mount air pump above the system's highest waterline
Who this is for
- Anyone running an air pump and airstone in a reservoir or DWC/RDWC system
- Growers who've had a pump damaged by back-siphoned water before
- Multi-airstone setups running several lines off a manifold
- Basically anyone with an air pump - it's cheap enough to fit as standard practice
Our take
This is the kind of part that's easy to skip and then regret. It costs next to nothing and takes minutes to fit, but it directly protects one of the more expensive small components in a hydro system.
Worth picking up whenever you're buying or replacing an air pump - fit one every time.
