Well the ammonia and nitrite have gone done and that is good. The nitrate isn't a concern. What are the readings of tap water that has been left to sit for 24 hours and directly out of the tap. Test some from the tap, then leave some in a shallow bowl over night and test it as well. I wouldn't add more biospira at this point, just doing water changes will be fine and the fresh water is never a bad thing for fish.