to add...
Dps can get bored very easily, thats why the need lots of plants and rocks and stuff to explore. ive also heard of some people changing their aquarum around once every couple months to keep them interested and for them to explore new places. i DO NOT reccomend this, they are preditorail fish like i said, and when you change the aquarium they will fight for new areas, they are going to do that anyway once the tank is set up. they will fight for dominiance, but that only happens once... so if you change the tank around itll happen again, and one might get killed.
there WILL be a dominiate.. its usually a male, but mine was a big female who as dominate.
to add about feeding, they simply will not eat flakes, and i had a hard time getting mine to eat frozen blood worms, they like seeing their food move, so i reccoemend only live food. live brine shrimp is fine but not a solid food, its just a lot of empty callories with no real vitemins or anything it.