New home with pool for about 6 weeks. 17000 gal with spa, ozonator with puck feeder. After about a month I thought I had it figured out, the pool was crystal clear, FC was running 2-3 and Boom I got green walls. I had been lurking about on this site but hadn't bought in yet. So now I check the cya and its over 100. I do a partial drain and get it down to 40 and decide to shock to 24 because I also see something funky in the deep end that looks yellow/brown and green about the size of silver dollar. I'm using 10% bleach now and the pool calculator but it is really using alot of chlorine for the first 18 hours will this continue? Also with cya 40 and FC at 24 is it safe to swim?