Mine attempted immediately as well, to jump out of the tank. However, I followed the advice of Colin from Zoa Collector, to place my eel in an acclimation box for nearly a week. I had some pvc in there for him to house himself in. For the first couple days, he was pretty stressed after the shipment, acclimation, then placed in the box. After a couple days, he began to calm down greatly. After 6 days, I let him loose in the tank. After he attempted to leap out of the tank, he swam straight down to the largest rock in my tank and chose his home. For the first couple weeks, he was barely seen. Now, I feed him every other day or so. I often see him sticking his head out of the liverock. Some days, I don't see him at all. I know though, he's very healthy. Takes a breath pretty much every second. When I first got him, probably due to stress, he was breathing very heavily and was taking breathes about every half second. Since you let him loose already, I would say leave him be. Don't want to tear your tank apart trying to catch him or stress him out any further. Maybe post a video of him later. ;) Good luck. How long did you acclimate for? I placed my guy in a bucket with the water and drip acclimated for approx an hour. I did 15 mins with an air stone to help boost some of the gas exchange from the water he came in with.