you, unfortunately need to start hatching brine shrimp, or feed them live zoo and phytoplankton, as a baby seahorse floats near the surface of the ocean in a heavy layer of plankton where they eat and eat until they get big enough. Definately isolate them as mentioned before or your other fish will eat them. They must be fed newly hatched brine shrimp that still have their yolk sac attatched as this is where they get a lot of protein from. You also need to enrich the brine with a vitamin formula such as zoe or selcon. They eat like pigs, as this is all they do for their first weeks as juveniles, and most die because of lack of food. I would leave tehm for now, and read up about culturing seahorse that way when they have babies again you will be better prepared to raise them!
good luck!
jon
