If by New World cichlids you mean Central Americans that water's fine. Even tank raised or properly acclamated South Amercans are good in that water. Unless you are keeping some newly imported blackwater species you should have no issues and even then while they may not breed, if acclamated over time they will be fine too. What is your hardness Gh/Kh in your aquarium? Have you tested your tap water for hardness and Ph? You should test streight from the tap and let some sit over night and test that to see if or how much it changes. What type of substright do you have?
It is best to leave the water alone trying to adjust water chemistry is very diffacult & or expensive long term and not worth the agravation. Unless of corse your gole is to breed Heckel Discus or Altums, U. Ferns etc.
