I'm on plain city water, no water softener, chlorine/chloramine treated by the water company. I use a 3 stage chloramine filter I got from the filterguys.biz. I tee off the cold water line under my bathroom sink.
I think Didysis drips without a filter--you have to ask him. But to drip w/o a filter, you have to really trust your water company, have adult stock, know what the chlorine levels in your water supply are--I just filter.
Call filterguys, see what they say. A water softener complicates things a bit.