re: Is it really okay run a pool pump while all suction or returns are plugged?

I had this same problem with my pool last summer.
I plugged each of my lines one at a time to see what was leaking, with the pump running and without. mine happen to be a return line about a foot away from the edge of the pool in a 90.

I made my own leak detector. I used one of my scuba tanks and made a gizmo to attach to the return lines. when I pressured up the one that was leaking, I could hear it gurgling under the cement.

then the fun began