housing a seahorse

[Bar16]

Is it possible to house a seahorse in a 5.5 gallon. I have a 5.5 set up cycled and loaded with live rock with nothing in it.

 

[CCall]

The only seahorse that can go in a 5.5gal is Dwarves. They need a tank that has no hydroids, bristle worms, etc.
They also eat only newly hatched baby brine shrimp.