Personally, I wouldn't poly until you've held a chlorine level from sundown to the next morning, and the stuff is still there. Until then, you've got something eating your chlorine. It can take days (took me 6 days with a mustard algae bloom earlier this year). Be patient. Make room in the recycling bin for bleach bottles. Brush twice a day.

Make sure you check your CYA level to make sure you are hitting it with enough chlorine.