Africans is a very generic term, what kind do you have?
If you have mbuna then the diet is on the right track. Catfish pellets are fine as a supplement since they're usually shrimp based. Any type of worm is very unhealthy for them. Brine shrimp makes a good supplement for most of them though. I've always found it messy on the tank, but many keepers feed vegetables as well - spinach, peas, cucumber, zuccini... that type of thing. Labidochromis is an exception, they share a diet similar to Aulonocara and smaller Haplichromines, and don't need so much spirulina in their diet.
Haplichromines, Aulonocara, and most Tanganyikans are preditors of some form, so all of that spirulina wouldn't be needed. Standard pellets and flakes are good for these guys, and invertabrate supplements like brine shrimp work well. They'll consume the catfish pellets as well. Gobies and tropheus are the main herbivorous exceptions from this lake, and should be on primarily spirulina.
