Congrats on finding him alive, I have one myself and have had him escape 3 times on me. Always finds his way under the stand. No matter how sure I am I cover every gap he gets out and usually overnight so I don't know how long he is out for but he was very sticky and dry, good as new within 20 min of being back in the water. I think I finally have all openings thoroughly sealed, no escapes in the past month or so. Also I recently added a piece of PVC with elbows on either end and buried it in the sand so that the openings are flush with the sandbed and he seems to love it and stays in there almost all the time and he has since stopped exploring the surface of the water at night. Just some food for thought.
BASALISK