I had to do this several years ago when I had the pump replaced. At
that time I listened to all the experts. The municipal water works guy
in the local town gave me a complicated formula based on the depth of
my well, the number of gallons in it, etc.

In the meantime, the local "good old boys," all told me to just dump in
a "gallon of Clorox."

The water works director also loaned me a chlorine testing kit to test
the PPM of chlorine at the house. I added the recommended amount of
bleach and the chlorine level never did reach the needed level. So, I
added several more ounces of bleach. Still no go.

Got frustrated and dumped the rest of the gallon into the well, and
"whaddya you know," it got up to the ballpark in the ppm.

Anyway, I didn't include the ho****er or the clothes washing, or come
to think of it, the dishwasher, last time....guess I will this time.