I'll keep this simple. I added my 1 pitcher of top off water last night at about midnight when I got home. This morning I woke up to a tricke sound from the sump. I probably lost about 4-5 inches of water in the sump overnight. I had to add maybe 5-6 pitchers of water this am. The light wasn't on in the tank but level looked ok. Skimmer looked fine. Nothing alarming right off the bat and then I had to leave for work so tell me...What happened last night???