What will happen to my aro if i don't put anti-chlorine and salt in the tap-water tank? Is it possible if i use rain water instate? Anybody here had this experience? 

rain there is quite unpredictable i'll sayDeLgAdO said:does it rain ALOT in singapore?
anyways yeah use dechlorinator for your arow, as for the salt, you dont need it, but it has its benifits.