Depending on how your water started out as, you could be "balanced" in 2 days or so. CYA takes the longest to fully dissolve but if he is measuring and testing properly he should have put the right amount by weight initially. That goes for all the chemicals. You need your own tf-100 test kit asap.
If this was a refill of your own Terry, I'd say you could have that water balanced in just a few hours (liquid gold stabilizer, bleach, and some acid perhaps). But since you are relying on a builder, most of whom use generic pool industry methods, then just "dump & go" with chemicals, it might take a few days. But like the others said, with your own TF-100, there is no guesswork. You'll know more abut your water after one test than the installer after a week. We sound repetitive at times, but the test kit is #1.