These fish are as hard as nails, i've kept mine in water ranging from mid strength brackish water (1.010 SG) to room temperature freshwater and it has thrived in everything. They do seem to have some problems with locating food and do best with smelly foods such as pieces of fish and mussels which they find easier to locate, they will also try and bite anything that their mouth comes into contact with so don't keep them with any slow moving or easily damaged fish.
Like all eel shaped fish they spend half their lives trying to escape so a secure lid with all corners covered with tape and any holes for equipment sealed is essential.
I have read various accounts that large adult specimens become very aggressive and can cause considerable damage if they manage to bite you as they have a jaw structure similar to that of lung fish.
