Tank 17 ('Congo') (species list in comments)

Reedfish (Erpetoichthys calabaricus)
African knifefish (Xenomystus nigri)
Gray flying fox (Crossocheilus oblongus)
Golden congo tetra (Phenacogrammus aurantiacus)
Congo tetra (Phenacogrammus interruptus)
Striped african glass catfish (Pareutropius debauwi)
Striped Barombi Mbo cichlid (Stomatepia mariae)
Benitochromis cichlid (Benitochromis nigrodorsalis)
Lionhead cichlid (Steatocranus casuarius) (not seen)
Bluefin dwarf cichlid (Enigmatochromis lucanusi) (not seen*)
Yellow kribensis (Wallaceochromis humilis) (not seen*)
Drachenfels`dwarf cichlid (Pelvicachromis drachenfelsi) (not seen*)
Ankasa hemichromis (Hemichromis spec. "Ankasa")

* I did see a cichlid I could not identify, which might have been one of these 3

My favorite Congo fish, the Siamese algae eater!

@Ebirah766 To be fair, algae eaters (as well as plecos) are often added as a 'tank cleaner'.