Ideas for a 30 gal tank

[Mattyice008]

So I've already got a 75reef, 30gal mantis shrimp tank, and now I have an extra 30gal that's been running for almost 2 years. Need ideas for some cool and exotic livestock.
Some of my ideas so far:
Dwarf lionfish
Some sort of eel
Sea horses

Tell me what ideas you guys have! I want to get something really interesting.

 

[StevenBell]

Iv always thought about doing a Monterey Bay type tank with cooler water,might be interesting!