I added my cories the other day and ya'll are right. They are great!! I love 'em!! In the begining my tetras would swim around but spent most of their time sitting still in the back of the tank. But as soon as I put them in all of my fish came to life (and stayed that way ). Now they swim and they will sit in the front and kind of show off. I LOVE CORIES!! Everyone should have them in their tanks. lol. jk.