How much chlorine do you need to add for the correct ratio?

The amount of chlorine needed depends on the specific pool or water treatment requirements, including the volume of water and the desired chlorine level. Generally, for residential pools, a target free chlorine level of 1-3 ppm (parts per million) is recommended. To achieve this, you can use a chlorine calculator that takes into account your pool size and current chlorine levels, or follow the manufacturer's instructions on the chlorine product you're using. Always test the water after adding chlorine to ensure the levels are within the desired range.