Raising Hippocampus erectus Fry
The major differences among raising the different types are the food necessary and length of pelagic phase.
If they are erectus their first food is newly hatched, decapsulated brine. Then to enriched brine with slow transition to frozen mysis.
Erectus are fairly large at birth with a short pelagic phase (1 - 2 weeks). They also tend to be enthusiastic eaters.
A good way to set up for fry raising is to purchase an inexpensive plastic fish bowl of about 2 gal. Silicone an air tube down from the top along the side about 3" down. Fill the container with water from the parent's tank. Bubble air in to cause light turbulence at the surface and a circular flow in the jar. Add very thin plastic items for the fry to hitch to.
Hatch brine -
http://oceanusinlandreef.org/Oceanus_the_Inland_Reef/Brine_Shrimp.html
and feed enough so they don't have to swim to far to eat them. Light from the side to keep the brine and seahorses off the surface. I add a few drops of phytofeast or similar product to give the seahorses better visibility of the brine and feed the brine if they survive. Do not over feed. Feed 3 - 5 times a day small amounts so it is all gone rather than a large amount that hangs around.
Siphon bottom of bowl every day and makeup with water from parent's tank. Do not do a large water change. In a week (depending on quantity and size) move to a 10 gal tall with a cured sponge filter and air bubbling. Siphon bottom daily.
Here is a link to an excellent paper on raising erectus. In my experience this setup works well if you have a large brood. It is difficult to provide the proper amount of food in this setup with smaller batches.
http://www.seahorse.org/library/articles/scaleerectus.pdf
If they are reidi - this will not work at all. Need to start with rotifers and pelagic stage is 4 - 6 weeks.
If you'd like to come out and see my setup just let me know.