Thanks for the reply, I read more today & expected your answer to be lots of chlorine. I did try to fill out the pool info. Under my ID if it took? The pool readings this evening are:
Fcl:2.5
Tcl:3.13
PH:7.2
Alk:170
CYA:High- too high for my reader 125+
Pool store says total hardness around 300

From looking at the best guess chart I'm guessing I need to have my Fcl around 2525 to shock effectively. I added 1/2 box borax & 3 Gallons 6% Cl. Will recheck tomorrow, & try to keep Cl up that high. I can't test real effectively that high without having to dilute & multiply.

Thanks again