I live in Atlanta and have a 20,000 gal SWG gunite pool that we have just placed the winter safety-cover on (my pool is nestled among dozens of trees). With the SWG, as we all know, the ph climbs and is lowered by adding muriatic acid. How can I add muriatic acid with a cover on? Is the only solution to unhook some of the safety-cover straps so I can peel the cover back far enough to avoid the acid hitting the cover? Then, how would I brush the bottom of the pool to avoid having the acid drop straight to the bottom? Also, what causes the ph to rise - is it the chlorine setting or the simple act of passing through the cell? In other words, as the water gets colder and the demands on the cell are reduced, does the ph stop rising?