Split from here: no-free-chlorine-t44900.html Butterfly
I am having a very similar problem with no free chlorine at spring start-up. I have a 16,000 gallon above ground pool - initially the pool store tested my water: TC 7.5, FC 0, Total Alk 184, Total Hardness 236, CYA 30.
I have added an unbelievable amount of chlorine and still have minimal FC readings. I have added 7 gallons of Pool Shock and 10 lbs of trichloro - looks like I am maybe finally testing FC at 1 but have not gotten it any higher.
Hard to believe I need to add this much chlorine - plus more. Any suggestions for me also? I do have a Taylor test kit so at least I have that going for me......which is nice. I always wonder what is the best and most economical type of chlorine to use in these situations. The pool store wanted to sell me 24 bags of Burn Out3 or 25 lbs of Zip Chlor - think these would be expensive options, correct?
Appreciate the help.