Welcome to USA. I bet there's a lot of members here can show you how to get started with a SW tank. For a SPSs, I will not go there if you're new to this hobby. It's harder than you think it will be. You need to understand and very knowlegable about the salwater columns before you become a SPS keeper. For your question, SPS eat fish poop(everybody know that) and zooplankton (roftiers, coppepods,......).
Happy reefing,
