I havent had a chance to change the sand yet, I tested my water at 10:30 last night and had a FC of 32.5 and CC of less than .5( it didnt even need a full drop to clear it), this morning at 8:00 I tested and FC dropped 1 to 31.5 and CC was still less than .5 Water is still a lime green color and very cloudy, cant see over 8 inches down. When I added all those bags of shock Xtra blue, I think it was 12 of them over a span of a week, copper was .26% of the ingredient. Is there a chance I`m dealing with a copper issue and not an algae issue? FC has been at or slightly above 30 for going on 5 days now