check valve on the airline

[jkatlantic]

Should I use a check valve on the airline? General Hydro said yes I could but they did not recommend it. Does it decrease the airflow?

[DW2]

Howdy jkatiantic, Yes, a check valve (or any other restriction, tee or elbow) will reduce the flow from the air pump. I have not read GH's reasoning for using a check valve, but would assume that it is to keep the water from the reservoir from 'back flowing' due to a power interruption. One can prevent a back flow by placing the air pump(s) higher than the water level of the reservoir(s), which is how I have mine setup. With the pump higher than the reservoir level, the water will not back flow into the air pumps when the power is turned off.