Sorry its Way to less Food for the fish. You should Feed your Fish 3-7 Times a Day. Unless in Nature coralfish Feed all the time. Its Not normal Feeling your fish only once a Day!
Its better to feed less amount but more often during the day.
Normal reeffish can get quite old. I have a pair of zebrasoma flavescens with the Age of 24! My Clowns are 11 Years old.
The other Thing is that you should keep reeffish in Pairs! Especially Tangs!
But!!! You have much to much Fish in your 60g Tank!!!! Hippo Tang will grow to 31cm!!! I could Not keep them in my 1500l Tank for more than 1 Year. They started to spawn and my Floor was wet everything evening!
Sure, if you keep feeding them less they will Not grow and die Sooner or later.
You will find more Information about Fish here: www.reeflex.net