What are the prettiest African Cichlids?

What do you think my African Cichlids need in their 20 gallon fish tank?

• I have a log(for them to hide), three artificial plants, filter and gravel. So what should I add? I have 4 African Cichlids and they're about 0.75 inches and they aren't fighting. They told me(Petsmart)that their maximum growth is 4.5 inches so that would be 18 inches which leaves me with 2 inches for them to have as an extra.

• Answer:

  First, the "inch-per-gallon" rule is seriously wrong for any fish more than 2 inches long. To summarize why: A 4.5-inch fish does not have 4.5 times the body mass of a 1-inch fish, it has around 20 times the body mass of a 1-inch fish. So the 4.5-inch fish generates 20 times as much waste, and needs something in the neighborhood of 20 times as much space as the 1-inch fish. Would you put 80 1-inch fish in a 20-gallon tank? I hope not. [The body mass increases roughly with the square of the fish's length, so a 2-inch fish is 4 times as large as a 1-incher, a 10-inch fish is 100 times as big as a 1-incher, and so on.] Second, I've found that Petsmart personnel are frequently misinformed about how big a species can grow. So I don't know if your tank is big enough for your fish or not. There are about 2000 different species of African cichlids, and they include one of the smallest known cichilds, Neolamprologus multifasciatus (a little over an inch [2.5 cm] long), and what is probably the largest known cichlid, Boulengerochromis microlepis (attains at least 40 inches [1 meter] in length), and just about every size in between. Few of them will fight at 0.75 inches, because most cichlids are still very young juveniles at that size. But as they start to mature, there is often trouble. If you can, find out what species of African cichlid you have. Then you will know what information to look for.