[Nemo]

I run check valves in my system.

1. clean them every time you do a water change, they have built in unions, take the ball out and wipe it off and wipe out the seat.

2. they do not reduce the flow, the check valve is a lot larger than the pipe size it conects to. This is to allow ( in my case) a full 3/4" of flow around the ball, so the 3/4" line is always full.

3. If you ever decide you do not want the check valve in your system, take the union apart remove the ball and what you have left is an expensive union.

4. you can always decide to drill your return pipe in the tank at a latter date, but you can not decide to un drill a hole.


Robert