Neither of your cichlids are piscivores, the Neolamprologus eats insect larvae and invertebrates in nature, and the Geophagus is an omnivore, eating mostly invertebrates it sifts in the substrate, and vegetable matter. That said if the tetras are small enough (bite size) and the tank is small enough the tetras don't have escape room, no cichlid will turn down an easily caught, high protein meal.
No other fish in the tank?
Do you have soft or hard water?
How often do you do water changes?