There is a kind of cover called a "leaf net" can go over even a solar cover that is very light. Otherwise, there's only the mesh safety cover that's meant to go on in the fall and come off in the spring. I've always used such a mesh safety cover on my pool, which, while an AG, is rectangular and has a welded-truss as a super-structure and uses much of the equipment that you'd use on an IG. I'm not sure you could use a safety cover on a lot of AG pools unless they were built into a deck.