I had two of these "freshwater moray" eels a long time ago. I had two in a long 40ish gallon tank. Mine grew about 2 feet before I had to move and give them away so they might get a lot larger.
These guys pretty much eat anything... Fish guts, squid, shrimp, etc. I usually just gave em whatever fishing bait was left over. They'd get in a frenzy if I gave em fish guts. They tend to eat at night at first but you can train them to be hand fed. Mine wouldn't eat feeder guppies after I started hand feeding them because they got too lazy to chase after em. Some owners will scatter the food around to stimulate hunting behavior but mine were too spoiled.
I think they prefer slightly brackish water but I'm not sure. They absolutely need caves/rocks/hidey holes since they're eels. Overall they were extremely hardy.