Ahli cichlids

Question
Hello.  I recently put an assortment of cichlids into a 55 gallon tank with new sponge filters (80gallon capacity each).  My fish were in the tank for not even 2 days and my Ahlis are acting so weird.  Their back fin will not move.  It looks almost paralyzed.  Some stay in the plant and others stay on the gravel, they do not swim.  All my other fish (red zebra, johanni, peacocks ect.) are completely fine.  The only main difference i can think of between the Ahlis and my other cichlids is that they are babies (around 4months old).  I tested the water chemistry and it was perfect.  Any ideas on what could have happened and what may be wrong with them?  So far one has died.  They are now in a stabilized 80 gallon.

Answer
You may have acclimated them wrong, or they may have been bad at the store.

Also, sponge filters are kind of obsolete, and don't do much. It would be a better idea to get a HOB or a canister. Also, look for a rating double the size of your tank. If your tank is 55 gallons, get a filter rated for 110 gallons.

-Nick