Happy New Year back!! I am grandson watching so I am going to be asleep at midnite I bet!! LOL.. AND feel much better in the morning too!!
It is all going to depend on your Ph and hardness: GH and KH.. Most fish stores wil test your water for U.. make a list to give them so they can write it down as they do it. Ph, GH and KH if they can. Some use testing strips so KH is not listed, just the general hardness..
So once that is done, deside from this:
African cichlids like a Ph of 7.8 to 8.4 and med to hard water.. They stay small, under 6" on most, have about 20+ per spawn as most females are mouth brooders, meaning they hold the eggs then fry in their mouths for 3 weeks.. Are very active in a tank, so U get lots of movement. ROCKS requrired as they are mbunas, meaning, rock dwellers.. Fake plants only as they wil eat live ones or just tear them up.. Sand substrate is best.. U can do 8 to 12 adult size in a 55gal..
American cichlids like a Ph of 6.4 to 7.6 and soft water conditions.. They can get to 12" depending on the species, Oscars to Jags/others, so a 55 gal is really to small..
Severums, Jack Dempeys=JD, Green terrors=GT and some others do fine in a 55 but to many at this size at adult, 8 to 10" and U wil need a bigger tank within a year..
So only 3 of any species is best in a 55gal at adult size.. An all male tank is best as a breeding pair of any of the above is going to cause death to the others once they spawn in the tank.. they are egg layers on rock or other deco in the tank. rock to drift wood is best.. Gravel of your color choice..
filters: I use 2 Emperor 400 on my 55gal tanks. ONE on both sides of the middle divider. This gives U 800 GPH=gallons per hour, on filteration which is great.. Best to purchase them ON line if U can or request a catalog and do a money order/check.. U can get two for the price of one ON LINE than from a LFS=local fish store..
http://www.fosterandsmithaquatics.com/f ... /3578/3579U can do 2 penguin 350 w/bio wheels and do 700 GPH and that is stil a great filter and cheaper too.. Dont settle for a smaller filter than this on GPH, they will not keep your tank clear like a emperor or the penguin will..UP to U.. Remember to leave 4 1/2" behind your tank from the wall so the filter wil fit..