Ok, so tomorrow (saturday) I'm going to clean the filter, the cover and raise the chlorine level like you recommended. It's chilly here in Minnesota these days and this weekend the evening temps are going to drop into the 30s with highs in the 40s. I understand lower temps slow the growth of algae, but will this have any affect on the FC and CC in the pool? Also we plan to officially close the pool for winter on Oct `13th. Just wondering if I need to be concerned about having high FC levels in the pool at closing time. I'm concerned and wondering if this will cause damage to our vinyl liner and pool equipment (for having high chlorine levels for extended period of time)?