thanks :) I'll give a fish list, though I'm afraid I'll get chastised if I've mixed species that are traditionally incompatible or require vastly differing water conditions

In my defense, I've had most of the fish in the tank for around a year, with no disease outbreaks, no fighting amongst inhabitants, and no odd/stressful behavior.
With that out of the way, here goes:
1
Jack Dempsey cichlid, ~6"
1 Venusta cichlid (have hard time finding info on this species), ~4"
1 unknown cichlid (LFS told me incorrect species, cannot identify... actually, maybe I can post a pic and you guys can help me identify it :))
1 black ghost knife
2 tiger barbs (used to be 4, over the months a couple have died.. one jumped out of the tank overnight!)
1 red stripe barb
1 large spotted pleco, ~6"
1 catfish, also unknown species (you can see him in the lower right corner of one of my pics above)
I feed them small amount of flakes, cichlid pellets, algae disks, and live feeders (ghost shrimp and guppies), so they get a diverse diet and everyone gets something to eat :)