OK.. Embarrassed as I type this, I decided it would be a good idea to backwash in the dark. I left the Multiport switch on Backwash, and went to sleep. The pool plump was NOT running, nor did it turn on BUT.. I awoke this morning to find my water line had fallen below the skimmer. I mistakenly did not return the multiport to "filter", but was amazed to find that the water would escape overnight (almost 10 inches). The suction was there, and the line was primed, so the water continued to flow from the skimmer opening. I will NOT make this error again, but felft the need to know if anyone else has done this. Oh.. My backwash line is underground, and drains away from my house... so... I never saw the water being drained in the dark.