I did the math once, and it made since at the time. (My hourly run time/% level) Figured the FC production per day, and it all added up. Feeling lazy now, so I'm assuming that the 1.6 lbs equates to trichlor per the pool math site? If so, 1.6 lbs, or 25 oz = 7.5 FC per day. (EDIT: That's 7.5 CYA...