Designed for pressurized CO2 systems
Essential for prevent water flooding out of the aquarium
Durable stainless steel construction

This check valve can only be used with a pressurized CO2 cylinder. The air from a regular air pump will not be able to pass through it. A check valve is used within airline tubing to prevent water from siphoning out of an aquarium and into a CO2 regulator. Stainless steel check valves are durable and will hold up over time keeping your equipment safe from leaks. A stainless steel check valve is the best choice when using CO2 as it will hold up better than plastic over a long period of time.

If the CO2 regulator is positioned above the rim of the aquarium, then a check valve is not needed. However, in most planted aquariums, the CO2 regulator is lower than the aquarium rim, which means that water will travel out of the airline tubing and all over your floors whenever the CO2 regulator is turned off or loses power. The check valve allows air to pass through in one direction, and it prevents water from passing through the opposite direction.

The arrow on the check valve indicates the direction of air flow. If you install the check valve backwards, then no air will pass through. Simply flip the direction of the check valve, and it should work again.

The best way to position a check valve is near the top of your aquarium. This stops the water at the rim instead of down near the pump where over time the pressure could cause a leak. Make sure your airline tubing is cut nicely and free of any tears. Check to make sure the tubing hasn't dried out over time causing the connection to be loose as this will leak in the event of a power outage.