Since I opened the pool in June/2014 (13,000 gallons above ground) Test results have showed No Free Chlorine. For last 4 years have used BioGuard products and never had this happen. Pool place told me to add 28lbs (over $100) Super Shock or drain water and start over. Water was clear & good for 3 weeks but as of last week No Free Chlorine again? Now they are telling me to add 15 lbs of Super Soluble also $100. Is they any other less expensive ways to bring up free chlorine? Can someone please help me with this problem. As of today, water looks clear and just a little haze.