OK, I can see several things:

+ Almost any time your pool is cloudy, you should be filtering 24/7. But, with a sand filter 4 hours per day is not enough even under ideal conditions.

+ You don't know how you're testing, which likely means you're a victim of a dealer testing (AKA chemical sales) program.

+ You're filling with well water which makes accurate testing even more critical.

. . . . Draining may still be a good idea, but definitely NOT something to do, till you have a clear plan to avoid this again.