We have just moved into a home with a pool. The CYA was 100 and FC 2. It has algae growth present. We have been told we need to drain the pool to control the CYA and then treat the algae. We are in the Pacific North West region so the swimming season is over for this year. Our question is should we drain the pool and treat the algae now or just close the pool, cover it and drain it in spring ready for the new plaster? We have a 36x18ft concrete pool which was chlorinated by pucks and had the filter running 24/7. Many thanks in advance.