For two seasons now, I've been wondering how we keep getting sand in our pool. Today it dawned on me that it is coming from our concrete coping. That explains why we get an increase after a heavy rain and why it tends to line the side of the pool and top step. We have had this pool and coping for 15 years now and we've never sealed the concrete. Was this a mistake? Is there anything we can do at this point to minimize the degradation of the coping? It currently looks fine structurally; but the surface is rough.