there are 2 fish referred to as the snowflake eel. One is commonly sold as a freshwater species (it is a piscivorous species, and needs brackish water. This is what you have). The other (the white, black, and yellow species) is the saltwater snowflake moray Echidna nebulosa. This is a peaceful crustacean feeder. Neither species will survive long term in freshwater. The Echidna nebulosa requires saltwater, and the Gymnothorax tile (the one in your picture) requires high brackish to full salt conditions. They will die if kept in freshwater long term.
