Those screens are great, but IMO for an eel you'd have to find a way to clip it on or really hold it down otherwise he'd just push it up. I have contacted that guy as well, he was very responsive and helpful. I just hadn't figured out a good way of keeping the top down with a strong fish pushing it up. I eventually moved my eels to a big stock tank with pvc tunnels covered by live rock and built the sides up with plexi to keep them in. Before I moved them I lost one of my eels while I was away for a few days. I had had him for years and he decided to leave the tank. It was covered with glass tops, but I must have left a section askew before I left. I would have found him and all would have been fine had I been home, but no one here knew to look for him. So I guess my point is, if the tank isn't covered he will eventually get out.