I am having some difficuly in holding a measurable chlorine level. reecntly i added a stain remover which required me to run my chlorine down to 0. Since then i have attempted to bring my chlorine back to normal levels and have been unsuccessful. PH, CYA, Alkalinity, Hardness are all at the recommended levels. i have added shock and the chlorine still does not hold. Any advice?

Who's recommended levels?
We like numbers:
pH
FC
CC
TA
CH
CYA
Clarity of your water?

We also need to know pool size and type.
How do you normally chlorinate?

Since you had zero chlorine for a while you're going to have to shock, and shock is a process not a product. You'll have to hold it at shock until you pass the OCLT. You'll also need a good test kit to tell you that.

thank you for the support. the process of shock is what finally allowed the free chlorine to hold.