Don't drain a vinyl liner pool completely.

No.

The water in your pool is doing more than just keeping it wet — it’s holding the vinyl liner in place against the walls and floor. Drain it all the way out, and that liner can shift, wrinkle, or even tear loose from the coping. Groundwater pressure from below can also push the liner up, causing bubbles or a full-on liner replacement.

If you really need an empty pool (major repair, liner replacement), you have to deal with groundwater first. That usually means installing dewatering wells or a sump pump in the deep end. And even then, a brittle old liner might not survive the stress of going dry.

Short version: don’t drain it yourself unless you’re okay with buying a new liner. Call a pro if you absolutely have to empty it.