It depends on the size of your system, they need a lot of room and produce a lot of waste... They are best fed with meaty seafoods about twice a week (bought from your local grocer). It is a good idea to ensure the moray is eating prior to purcahsing from your LFS
(try not to use live feeders!). With most Morays you must make sure the tank has tight fitting lids or a hood as they love to escape and are very good at it.
I love snowflakes but be very careful with what you put with them... they can be quite aggressive and any small tank inhabitants will in time become a tasty snack... Good luck. P.S. I am currently cycling a 180gallon FOWLR
for a snowflake and a lionfish.... cool