You can feed all kinds of seahorses and Syngnathus pipefish with frozen brine shrimp, mysis as well as ghost shrimp (cooked if available). For alternation also small feeder fish can be given. The smaller pipefish like brine shrimp as well as small pieces of mysis.
Add a few drops of vitamins to the frozen food or inject the vitamins into larger pieces of food once a week.