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.