The initial motivation of starting a macroalgae tank is to grow enough pods for Mandarin fishes which also serve as a good 'catch' for frozen food. Usually the feeding is done targeted onto a bunch of algae next to the Mandarin fishes & seahorses.
Here is a video of both the Mandarin and seahorses feeding on enriched brineshrimp, sometimes when i'm lucky, both of them will be nipping from the same spot!