I've got a feeding plan set up for these sea horses. Turns out amphipods eat seaweed. I've been scraping the algae from my algae scrubber and dumping the biomass into a 5 gallon tank running off a sponge filter. There seems to be many amphipods breeding in the scrubber, so I decided to harvest them. The amphipods population seems to have been expanding and consuming algae faster than I could feed them. I caught 9 seahorses last weekend, only kept a couple of the smallest ones. I think I can keep them indefinitely, with food grown from the scrubber. In the photo I did bring a bag of ulva back from the ocean to help boost the amphipod population.
NOTE: after getting the look down to eat new life spectrum, I was not able to feed it often enough for it to maintain its weight. It feeding habits are like anthias. I will not try to collect those in the future, unless I can feed it soft food every few hours.
The burrfish, killifish, spearing, gobies and the blenny took to pellets right away.