Mated pair should be three

[Durbelethwen]

On diver’s den I found a mated pair of chromis http://www.liveaquaria.com/divers-den/product/380608/acares-midget-reef-damselfish-pair while doing research I read that the are best in odd numbered groups. If I buy them do I need to buy a third fish to school with them. 

Also does it have to be the exact same kind? I saw on regular liveaquaria that they are out of stock. I also have a lone clown fish.

[RayWhisperer]

Chromis are best kept alone. Hopefully, the bond a pair has would hold in captivity. Nothing is guaranteed, though.