You can pop it back in yourself.

Yes, if the liner hasn’t torn and the track isn’t damaged, you can fix this. The tool you need costs about $10 and is called a pool liner lock tool (or liner wedge tool). It looks like a plastic hook with a curved end.

You slide the tool under the liner, push the edge back into the track, then pull the tool out while holding the liner in place. Work along the problem area slowly. If the liner is tight or the water level is low, you’ll need to lower the water a few inches to reduce tension. If the liner is cold and stiff (early morning or cool weather), let the sun warm it up first – it gets more flexible.

Don’t use a screwdriver or anything sharp. You’ll poke a hole. And if the liner is old and brittle, any attempt might crack it. In that case, call a pro. But most of the time it’s a ten-minute fix with a $10 tool.

Future You deserves not having to look at that saggy liner all summer.