kiddie pool startup

We got my daughter an intex pool, 12' in diameter with a water level at 20". How do we implement the bbb method? I know what t he letters stand for but I can't find any specific instructions/measurements. Also we have been using it for a week very haphazardly, do I have to drain it and start again?

membership upgraded.

SS recipe here: Super-simple-pool-chemistry-recipe-for-Intex-type-pools-start-up-amp-routine-care

If your water is not really cloudy, you don't need to drain. If it is, you'll have nice water much faster if you do drain and refill.