How frequently do you all do this? I closed a couple of weeks ago and have pumped (well siphoned actually) off water twice. My concern being that as rain accumulates it adds more and more weight to the cover, and will continue to push water up the walls or eventually tear the cover. I did leave a fair amount of slack to allow for this to some degree, but not sure if I am being overly paranoid. Do I have more of a safety margin than I suspect?