I used to have a 16" fire eel but he jumped from the tank. Ensure your lid is very very tight. Mine was and had 3 lb weights holding it down but he still managed to move it.
125g - FX5 - CF500UV - Bichirs - Catfish - Clown Loaches - Oddballs
40g Breeder - Fluval 306 - HW402B - Grow Out Tank - Clown Loaches - Leopard Leaf Fish