I thought of that (amphipods, etc.) but they would have to seed the tank first and the sheer numbers the sea horses could consume would be staggering. I feed live feeder shrimp to my sea horses and they will eat more than they can digest. I have seen them poop out full shrimp ! They have no stomach so it doesn't take long for it to come out the other end. They will eat as long as food is available. Sea pigs is a better name for them.