I posted about a month ago a problem I was having with my SWG not being able to keep up. I needed to properly shock the pool, which I did. I have been closely monitoring the FCL levels since then, and in the past few days I notice they have been dropping, they held steady for about 30 days. I did the overnight test last night and the pool went from 3.4 to 3.0 FCL overnight. Clearly I need to shock the pool again.
Why would I need to shock the pool again just a month after I shocked it before? This can't be normal. I even have been adding the "magic powder" (oxidizing shock, potassium monopersulfate) every week or so to try and avoid this.
I noticed about once per 7-10 days the water would get very slightly cloudy. A light milky haze that you could only see with goggles underwater when you swam. When it got like that I would add the Oxidizing Shock and it would go away.
Is something happening to my water to make me have to shock it like this? For about 30 days the chlorine levels were fine with the SWG at about 30-40% for 5 hours a day.