Thanks for the reply. I did cover it already. But I can remove it for a few hours to add winterizing solution and stir the water if I need to. I am leaning towards not adding anything and doing a test/check every few weeks over the winter. (I distinctly remember the tech last fall pouring a gallon container of something into the pool just before covering it, so that's what I was going to do also. Now I'm not sure.) I will post later if any test strip results are troublesome. Thanks, again!