I wouldnt run it with that low of chlorine. I ran mine with 80ppm cya and FC at 5 for a long time with no problems but as soon as I got kids in the pool for a long time, their eyes started burning and the water would get a slight cloudiness and I could smell the chlorine alot. My CC went up past .5 after one weekend. I shocked it and now I keep my FC at 8-10ppm and no more burning eyes and no more cloudiness of chlorine smell after alot of swimmers. Next season Im gonna run a lower amount of CYA maybe 30-40 and see if I can get away with running a FC of about 4-5ppm.