I would have the young woman add 1 gal bleach each evening and keep the pump running during your absence. The bleach will add about 4 ppm FC and should be enough to keep the water clean with the CYA level you've reported. I wouldn't even ask her to test, just add the bleach. Do show someone at the house where you add the bleach and how you do it so they can pass that on to her, and give plenty of cautions about bleach splatter so she doesn't ruin her fav jeans