Winter Closing Playbook
Close the pool with clean water, balanced winter chemistry, protected plumbing, and a cover setup that is actually safe.
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Guidance provided at best effort for educational purposes.Read Terms →
Do not hide a problem under the cover
If the pool is green, visibly contaminated, or failing overnight chlorine checks, clear that problem before closing instead of relying on a winter kit.
About your current CYA
Your last known CYA is 30 ppm. Use it to make sure your final FC is still within a sensible operating range for your pool rather than defaulting to a one-size-fits-all “SLAM close.”
Deep clean before shutdown
Organic debris left in the pool is future chlorine demand and future stain risk.
Balance around defensible winter ranges
Use ranges that protect the surface and equipment instead of magic numbers.
- → For plaster and aggregate pools, pay extra attention to CH and saturation index before closing.
Final sanitizer step
The goal is to close with clean, adequately chlorinated water, not to publish a universal 'close at shock level' rule.
Winterize plumbing and equipment
This is the mechanical heart of the closing process.
- → Never use automotive ethylene-glycol antifreeze in pool plumbing.
Set water level for the cover system
Water level depends on the cover strategy and the winterizing procedure, not on a universal depth rule.
Treat the cover as a safety system
The closing is not finished until the site is secure.
Resources
PHTA winterizing tech note
Use PHTA winterizing guidance for baseline winter chemistry ranges and antifreeze cautions.
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