http://www.SwimmingPoolSteve.com - You want to maintain a free chlorine level in your pool between 1 - 3 parts per million (ppm) and the amount of chlorine that you will need to achieve this will depend on how much bacteria and organic debris is in your pool water. Supposing your cyanuric acid level (pool stabilizer) is in the right range then you would simply add chlorine every 12-24 hours to your pool until such time as you overcome the chlorine deficit and can build a chlorine reserve of 1 - 3 ppm.
If you would like to learn more about pool water chemistry and how to balance your pool water then read this pool chemistry crash course by Steve: http://www.swimmingpoolsteve.com/pages/chemistry.html
