Hi gang, another winterizing question from a neewbie (2nd yr pool owner, first time self-closing.) Do Pool Cover Clips actually hold the cover firmly and taught to the pool's edge? I have an air pillow in the center and I want the cover to be tight, creating a nice downward slope for rain to run off and avoid getting puddles. So, does the cover stay firm with the clips or does it eventually sag? I have heard of using milk-jugs or bungees to keep the cover taught. But the clips - if they work - would be safer and easier. Thanks for your help with my last post and for all the valuable info the forum has provided! Steve (12x24 AG Oval.)