We have small one, I put fish and stuff in it I catch. It's a pain in the ass though. I have a huge supply of salt water so we try to replace 25% of the water a week with fresh stuff.
It's not the normal setup by any means and it's pretty much like a galdiator pit in their. Kill or be killed. Alot of work catching the right food for each to eat.
The seahorse we let go because it would only eat very tiny fresh shrimp (and they are a bitch to catch) and to do it every day was too much.
