This year I have the mindset that I am going to maintain as high a level of FC's so as to not cause harm to my swimmer guests. Right now my FC is 5, and my kids swam for severall hours this past memorial day. I can smell "chlorine", near the pool, but my kids had no problems at all. No red eye, or irritation. Is FC of 5 too high? OK ? how about FC of 6? Thanks!