CHLORAMINE DOES NOT EVAPORATE. I learned the hard way, and it blows. Yes, you need a RO filter. I've been using a cheap one lately just for my plants in veg, and it seems to be working alright. You can get good ones for $100, so look around before you buy.
And not to sound like a dumb ass (but oh well), but I use RO filters on my drinking water, too. Chlorines and Chloramines are not only bad for our plants, they are bad for us, too. It's funny, I have a pepper growing out in our garden that I was giving straight water from the hose. It was literally stunted! Until, that is, I switched over to filtered water, at which point it has taken off like a weed growing again. I shit you not. So think about how it affects everything.
Hope everyone is well in the world of Super Soil.