Custom is the only option for irregular-shaped pools.

Yes. You need a custom cover. Don’t try to fudge it with a rectangle cover and weights.

Irregular pools — kidney, freeform, lazy-L, whatever — have curves that a standard cover won’t hug. The gaps let in leaves, debris, and worse: they become a safety hazard. Pool covers are meant to be tight. Loose cover = someone could slip under.

Measure the pool at its widest and longest points, then find a manufacturer that makes custom covers to your exact shape. Many pool supply stores do this. Expect to pay a bit more and wait a week or two. Worth it.

If you’re just covering for winter and don’t care about safety, a heavy tarp and water bags can work in a pinch. But you’ll still get leaves. And it’ll look janky.

Future You will be happy you spent the extra fifty bucks.