For an inground pool, lower water only to the level specified for the pool, its winterization method and its cover. Do not drain it completely for routine winter closing. There is no single distance below the skimmer that applies to every concrete, vinyl-lined or fiberglass installation.
Identify the construction, cover and plumbing arrangement before changing the level. Groundwater and the pool’s structural requirements can make excessive draining dangerous and costly. Ask the builder or manufacturer when the instructions are unclear.
Why a generic depth is unreliable
A solid cover, mesh safety cover and automatic cover can have different water-level requirements. The cover may depend on water beneath it for support. Meanwhile, the skimmer and returns need the winterization method specified for that installation. These requirements must be considered together.
Latham’s closing guide distinguishes climate conditions and directs owners to manufacturer instructions. A number from one section of a general guide should not override the manual for your cover or pool.
Get a written target and method
Record the pool type, cover model and relevant equipment. Ask the installer to specify the winter level, how to measure it, how openings are protected and what to do after heavy rain. Photograph the correct reference point so future checks use the same measurement.
If the pool has a history of leakage, liner movement or groundwater problems, raise that before draining. Do not operate hydrostatic devices, remove drain components or empty the shell as an improvised response. These are matters for a qualified pool professional.
Water level is not plumbing winterization
Water can remain trapped in pipes and equipment even after the pool surface is lowered. Pumps, filters, heaters and other components require their own manufacturer procedures. Closing a cover also does not winterize those parts.
Have unfamiliar buried-line winterization performed by a qualified service provider. Do not connect an air compressor and guess at pressure or valve positions. Use only specifically approved winterizing products where required; automotive antifreeze is not a substitute.
In a mild climate, the appropriate plan may involve continued operation rather than a full seasonal shutdown. That requires equipment-specific freeze planning and attention to outages, not merely a different drain depth.
Keep the cover and barriers effective
Install and maintain the cover according to its instructions, including the permitted water level beneath it. Follow the manufacturer’s procedure for removing accumulated water or debris. Never enter onto a cover or ice to perform maintenance.
Ordinary floating or debris covers must not be mistaken for safety covers. Maintain fencing, gates and other access protection through winter. Pool Safely’s year-round guidance applies even when swimming season has ended.
Check through winter and plan reopening
Monitor the level and visible condition after significant weather and at the intervals your service provider recommends. Unexpected loss, excessive accumulation or changed cover tension deserves attention. Do not pump water out indefinitely without knowing whether it is coming from the cover surface or the pool itself.
Before reopening, arrange inspection, equipment recommissioning and water treatment appropriate to the pool. A winter level that looked satisfactory does not establish that every component is ready to run.
The useful answer is the documented level for your installation, supported by a complete closing procedure. It is not “below all the jets,” and keeping some water in the pool does not eliminate the need to protect its plumbing.
