I hope that my family is among those it doesn't affect.

Tested the water again this evening. The pool does get full sun from about an hour after sunrise to an hour before sunset.

pH - 7.6
FC - 2.5
CC - 0.5
TA - 160
CYA - ~20

The pool was treated with dichlor (recommended brand from Sam's club) up to 15 ppm, will test out again in the morning to verify it isn't losing 1 out more ppm overnight and has .5 or less cc. With the comments received here, I'm feeling more confident in achieving good water chemistry and having a clean safe pool at the in-laws!

Thanks for all the information that is shared here!