First off, THANK YOU for helping me literally have a trouble free pool this summer. Following the advice on this site made it easy. I have to close my pool today, have read the winterizing article and am comfortable with everything in it - I did buy a winterizing kit from Viscount pools and it included a sequestering compound to remove scale. I do not have hard water or any visible scale, my CH is 300. After doing so well and with a new liner this year, I do not want to mess it up now. The kit also included an oxidizing shock with Potassium Monopersulfate & Dry granular winterizier. I would appreciate any guidance on the necessity of the oxidizing shock as well. I am in Michigan, we are having a freak 85 degree day, so I am trying to work with it 