I am going to try a mesh cover this year which is supposed to let the water through, so no siphoning. However, when things are frozen and its snowing the mesh won't matter much so I will still use a pillow, but when it warms up a little I am hoping it will drain through. Makes sense to me, but I have never used a mesh cover before. I am still considering not covering, like Watermom, but for some reason that is a mental hurdle for me. Leaves, animals, kids, liability, all tumbling around around in my head saying "cover you pool"!