Keep your pH within 7.1 to 7.8, ideally 7.4. Consider adding Potassium monopersulfate to assist your chlorine additive. Some people will disagree with this but I fought with free chlorine levels for the past 3 years. More chlorine (7 lbs of lithium hypochlorite) was added and the next day, my free chlorine level was 0!!! Chlorine evaporates and quickly forms chloroamines. No more free chlorine. Use the PMS to snatch up the amines (urine, suntan lotion, sweat, etc) leaving the chlorine free to kill bacteria. My water has never been clearer and my chlorine bill so low. I am now able to keep my floaters filled with tablets and no longer have to use the granular hypochlorite.