New chiclids

Question
Are electric yellow chiclids tame and is fine grain sand and plants nessecary if so
what are the positives of these. can they live in a 55 gallion tank

Answer
I don't know of any fish that are "tame" however if you mean docile then as far as Cichlids are concerned they are not as aggressive as most however they can be especially if they are trying to establish territory.  No aquarium sand is not necessary, normal aquarium gravel is fine.  Live plants are a good idea, they help to keep the aquarium clean and the water well oxygenated as well as help the fish to be more relaxed.

Best,
Craig.