so recently i have developed a little fish crush on several lake tang and i have an empty 75 gal. my problem is i know almost absolutely nothing on how to keep africans. the fish i have my eyes on are calvus, shellies, and cyprichromis leptosoma.. what would be a good stock list?.. if it can even work.. im planning for sand substrate and aside from that rocks for the calvus.. is that good or are there certain specifics that im missing?