Yes 3-4 gallons until you start to see the water clearing up. The leaves and debris are also using up bleach big time, and until they all come out, the bleach is being "sidetracked" so to speak. Don't forget to check the skimmer and the pool pump strainer basket frequently.

Once you get your testing kit, read the instructions carefully, as you may get a different effect for the chlorine value than what you expect. That is because you may have more chlorine than the indicator can handle. Someone with more experience will be able to help you here.

Post your numbers so we can help you further.

Pat