My Advice On Seahorses Are This. Do Not Get One Unless You Know What Your Getting Into. Most Seahorses Need Live Mysid Shrimp, Not Brime As That Has No Real Vitamins For Them, Giving Maybe As A Snack Only. I Bought This Tank With The Horse Already With The Tangs And Others. But My Advice Is This, You Should Have A Seahorse In A Tank Only With Seahorses Because They Will Eventually Starve And The Other Fish Will Eat It All Before He Gets To It. Yes, You Can Put The Horse With Other Non Agressive Fish, But I Wouldnt Advise It. I Gave That Horse To A Friend. I Couldnt Bare To See It Waist To Nothing In A Few Months. If You Are Going To Do This, Make Sure He Eats, Maybe Get A Surringe And Put The Live Mysid Or Frozen Mysid In Front Of Him So He Gets First Take. But Eather Way, Its Alot Of Work Unless You Want Just A Horse Tank.i Hope This Helps As I Had Many Seahorses In The Past.and Yes, Seahorses If In A Tank With Other Fish Need To Be With Non Agressive Fish Only.good Luck And Tell Me What You Do...