Last year, I battled twice with coccidiosis in my chickens. Everyone was on Purina Start and Grow medicated for 20 weeks, including at 8 weeks and 14 weeks when infection occurred. I again noticed an infection in my new chicks (7 weeks) just this morning. I was the feeders and water jugs every other day and change the litter monthly or sooner. I also let the flock free range daily when it is daylight (6:30 a.m. - 8:00 p.m.). I am not sure where I am going wrong here. Perhaps you all know where I might be going wrong! Any help is greatly appreciated!