#WelcometoR2R!!! Although there are many options, a commonly used feed for clownfish is @reef Nutrition’s TDO Boost pellets. Good luck with whatever you choose!
Welcome to the forum!
Most important is a good quality pellet. I’d find out what your lfs feeds them and go off of that.
They also will eat the pods (little invertebrates) that grow in the system.
Actually Reef Nutrition's TDO Chroma Boost as @Peace River mentioned is a solid choice. Also most omnivores seem to like it. My firefish prefer it to frozen Mysis, pelleted Mysis, even copepods.
Edit-- just noticed it was your first post. Welcome to R2R!