I keep a seahorse in a reef tank with clams, soft and LPS corals such as acans, favias, plates, candy cane, and cats eye. Definitely a lower flow tank but enough to keep the corals happy and the tank clean.
I also picked out some unusual tank mates that won't out compete the seahorse for food. I only feed my seahorse once a day and the other fish every three days or so.
I've had the seahorse for over 8 months with no problems.
Looks a little different these days but you get the idea.
