I was thinking about starting a new thread for this question but it's info that might make sense in this thread.

I have a PVC pipe that appears to be some kind of by-pass. It runs from the inlet piping (just above the ground on the piping leading to the pump. It's connected to a T on the main drain pipe) to the outlet side (where it has it's own shutoff valve). I have left the valve closed because I'm not sure what it's for.

Any ideas?

Thanks.