Hello! Brand new to pool ownership and my dad recommended TFP. We have been reading zero FC for well over a week now. Prior to this we had added some Leslie’s Perfect Weekly and Ultra Bright that had been left behind by the previous owners, in addition to cleaning the sides with a magic eraser—all of this per the marked instructions and prior to discovering TFP. When the problem began we drained some and added fresh water per recommendation from previous owner who said the CYA was high when he left. CYA is about 40 and PH 7.0-7.2 but still zero FC. Yesterday we practiced the SLAM process using powdered Clorox dichlor (all we can find easily around here). Maybe we are doing it wrong but it is still reading next to no FC. How long does one need to continue SLAMing generally? How do we determine what is eating up all the chlorine? Any suggestions on what to do next? TIA