Intex pool how much chlorine to put in a 20x48?

First you test the water with a decent test kit. By either using 12% liquid chlorine and or a combination of liquid and tablet or granular chlorine. You can determine by testing the next day or later that same day how much more you need to add or if you have added enough. Frequent testing will give you the experience and history of what you need to do to maintain sanitation levels. Don't skimp on your choice of sanitizer.