CORAL NOOBIE I seek help!

It is not food but coral DEFINITELY need it. They need calcium and alkalinity and magnesium. It's not optional if you want to keep coral. In order to grow/live and build their skeletons, even soft corals need it to some extent. Don't get too hung up on the word "supplement".

 

A hippo tang can grow up to 10+ inches long. Unless you have plans to get a larger tank or trade him in when he gets bigger he will outgrow your tank rather fast. You are already rather heavily stocked, and tangs require lots of oxygen and food and will contribute a lot more bioload than a damsel and a neon goby, I don't think that is an even tradeoff in bioload. Keep in mind those fish will grow, even if they're 1" now what are you going to do in 6 months when your maroon clown and hippo tang are 4+ inches?

Hate to sound so negative but I really think keeping adult sizes of fish in mind is the way to go when figuring out stocking plans.

 

K+ when purchasing livestock you have to think of how big the fish is going to be. Everyone might get along now, but when they are larger and getting in each others way, someone is going to end up hurt or dead, not to mention the bio-load they will have.