How do I get softer water in my aquarium?

i live in an area with hard water also and i keep fish that prefer soft acidic water. seachem's acid regulator and peat moss in the filter. i put the peat moss in an empty filter bag and put it in the filter. it gives a tea color to your water, but it softens it. if you use carbon in your filter it will help reduce the tea color though. a neighbor of mine who keeps discus actually sets up a bunch of full five gallon buckets with a bag of peat in each one and lets them sit for a few days before adding it to his tank. its much cheaper than an RO unit. as far as a filter, always get something rated a little higher than you need is my advice.