Is it a swim tank or reef. Are there other natural foods for your fish to eat and pick at or just plastic and nutritionless coral skeletons and sea shells? Daily is best though either way. Just keep an eye on your tank’s nitrates.
I feed everyday. Tank consists of multiple puffers and triggers,Harlequin Tusk... mostly carnivores. I feed them LRS chunky, krill, squid and clam strips daily. I feed clams and mussels 1-2x per week. Seaweed daily as well ad the triggers and Foxface devour it.