So back 35yrs ago.. (yes when I was 15....) I had a 50gal. I had the latest in tech with undergravel filter driven by "powerheads", crushed coral, and a canister filter. I had a snowflake Moray, Niger Trigger, Volitan Lion, Yellow Tang, Pearlscale Butterfly and the Domino Damsel that survived the tank cycle (yeah back then we cycled the tank with damsel fish... :-( ). I had to do weekly 5g waterchanges and I was happy when Nitrates were below 60!!! (didnt know any beter) but had that tank for 5yrs with ALL the fish healthy and when I sold it the tank ran for another 3yrs (when I lost touch with the owner). Oh and between the Snowflake, Lion, and trigger I went through 15 "feeder" goldfish a week... I used to keep the feeders in a 5g bucket and buy them 50 at a time (25% discount for 50+ feeders). Oh the good old days... NOT :-(
So yes you can have a Snowflake in a 50g... would I do that again... nope...