Hello. Yes, watch out for eels under your heels. If you leave any space at all and they can get their noses out, the rest follows. My Snowflake escaped twice and spent the night on the floor. I was pretty surprised. It survived both the fall and the time out. Of course it was a warm summer night. My understanding is they naturally come out of the water and explore the shore looking for stranded crustations. As Snowflake got bigger she was stronger and could actually push on the top. I cut plastic to fit exactly around the openings at the back of the tank and weighted the top and back with glass weights. They will eat almost any sea food offered in my experience. Snowflake loved shrimp from the market. Oddly, she preferred it cooked. Don't feed only Krill, there isn't enough nourishment in it, and be sure to change 20% water regularly. (I did so every week) It is very interesting that you have a spotted Leopard. It sounds like you are experienced with Morays, but just reminders and especially watch your fingers, feed with a stick, NEVER put your hand in the tank. They are fast and the bites infect immediately. ESP the Leopard. That Leopard is going to need a lot more care than the Snowflake IMHO
. You might contact Saltwaterfish.com. They sell the Leopard eel and will probably help you out. They are VERY agressive. I agree with the comments regarding a good deal of open space for thrashing about and a formation of rock for each of them that provides enough space for the entire body to get under. Be sure to vacuum under the rocks regularly. Feces are hard to spot. Have a really good flow of water. My only problem with Eels is they are a species only tank, but on the other hand they are really personable, in a rather ferocious way, and super interesting. Sounds like you took them on because you felt so sorry for them. I don't think they are ever really happy in a tank and I have a prejudice that they should be a species that is discouraged in the marine trade. As far as I am concerned it is like trying to domisticate a Lion or a tiger and the tank, no matter how big, is never big enough. Since you have taken them on, I suggest you hunt for two of the biggest tanks you can find and dedicate them to the eels. Try surrounding cities with larger populations. sometimes club members have extra tanks they will lend you for the dration. Be prepared to spend a bit of $$$ on salt. I have heard they do OK with fish that are quite a bit bigger than their own mouths and very active. I have a friend who has kept his for years with a Trigger. Good luck and they are lucky to have you.