feeding inverts

I have a 15 gal tank with a pair of clowns, 1 yellow goby, 1 pistol shrimp, 2 scarlet leg hermits, 1 Halloween hermit, 2 nessarius snails, 1 fire dart fish, and a variety of corals (1 hammer frag, 6 different varieties of zoa frags, 1 hobgoblin frag, 1 stylocoeniella frag, 1 stylophora frag, 1...

Hey y’all. I’ve been trying to figure out what kind of urchin I have for a week and I can’t seem to get any answers. Google certainly hasn’t helped, but I probably am not looking for the right thing! I really would like to know what type he is so that I can look into the best practices for care...

I recently got a new fighting conch for my 30l tank. After cleaning the sand in my tank for a few days I started worrying that he might not have enough food as my tank is very new. Does anyone have an idea what, and how to feed them, as well as how many times?