I've been shocking my pool for full 9 days now since I opened it. I raised the FC from 0 to 16 and have kept it there. For the past few mornings, the FC would be 14 and then I would raise it to 16, same in the evening (FC 14). It seems that I lose 2ppm overnight, but my CC is 0. Should I keep the level at 16 until it stays there overnight or since the CC is O, I can assume all is well and let it go down? btw, we had a lot of rain in the past week.