1 gallon of 8% household bleach adds about 8 ppm to 10K gallons of water.

A slightly simplified version of WaterMom's answer: when people come to the forum they almost always need to add chlorine, but only rarely can we fully trust their description of their pool water's condition. They can almost always add bleach safely.

If we recommended cal hypo, and their calcium was already too high, we could turn their pool to 'milk'! If we recommended dichlor, and their stabilizer was already 200 ppm . . . we'd make it worse. If we recommended trichlor, and their pH was low, we could damage their pool.

If you check some threads, we often recommend other chemicals, once we know more about their pool.

. . . membership upgraded.