Pool Closing Kit and Shock Bundle - Winterize Up to 35,000 Gallons

Our review of this pool closing kit finds it best for homeowners who want a straightforward, all-in-one winterizing solution that limits spring cleanup. The kit pairs a chlorine-free closing system with six 1 lb pre-measured bags of cal-hypo shock so users can both protect the pool through winter and sanitize effectively before closing. For anyone who prefers clear instructions and products designed to reduce algae, staining, and equipment stress during the off-season, this bundle delivers practical chemistry and sensible accessories in a single purchase.

Key Features

• Complete winter protection: Chlorine-free closing chemicals stabilize water and help prevent algae growth, staining, and damage to pool surfaces and equipment during the off-season.
• Pre-measured sanitizing shock: Six 1 lb bags of cal-hypo granular shock provide added sanitizing power to eliminate bacteria and organic waste before the pool is closed.
• Algae defense floater: The non-chlorine winter floater controls carbon dioxide levels to starve algae while keeping chlorine-sensitive surfaces like vinyl liners safe.
• Targeted stain treatment: Winter Stain-Away and Pure Clear + NoPhos address staining and phosphate-related clarity issues so water is easier to reopen in spring.
• Handy accessories included: Winter Sorb and a winter pool floater make it easier to manage debris and distribute chemicals without extra purchases.

Who It's For

This bundle is ideal for backyard pool owners with above ground or in-ground pools up to 35,000 gallons who want a single purchase that covers both winter stabilization and a pre-closing shock treatment. It suits people who value clear, guided steps for closing and who prefer to avoid leaving free chlorine in contact with sensitive liners during winter.

It is less appropriate for users who need specialty treatments beyond stain and algae prevention or who prefer a purely chlorine-based long-term sanitizer. Professionals managing many pools or very large commercial installations may want to source concentrated components separately rather than a consumer-focused kit.

Pros & Cons

Pros

• Convenient all-in-one kit reduces the number of products to buy and simplifies closing steps.
• Includes pre-measured cal-hypo shock bags for predictable sanitizing before closing.
• Chlorine-free winterizer and floater help protect vinyl liners and reduce algae risk without constant chlorine contact.
• Accessories like Winter Sorb and Pure Clear + NoPhos improve clarity and stain prevention for an easier spring opening.

Cons

• The kit is sized for pools up to 35,000 gallons, so very large pools may require additional product.
• Some users who prefer a single-method chlorine approach may find the mixed chemistry unfamiliar.

Specifications

Brand	In The Swim
Coverage	Up to 35,000 gallons
Included shock	6 pre-measured 1 lb bags of cal-hypo granular sanitizer
Kit contents	1 qt Winterizer, 1 qt Winter Stain-Away, 3 lb Chlorine-Free Shock-Oxidizer, Winter Sorb, Winter Floater, 3L Pure Clear + NoPhos
Sanitizer type	Calcium hypochlorite granular (cal-hypo) shock
Floater type	Non-chlorine winter floater for algae control

Our Verdict

The kit is a practical, cost-conscious choice for residential pool owners who want to reduce spring work and protect surfaces over winter. With pre-measured shock, focused stain prevention, and a chlorine-free floater, it balances sanitizing power and gentle winter chemistry, making it good value for most above ground and in-ground pools up to 35,000 gallons.

Frequently Asked Questions

Will this work for a 20,000 gallon pool?
Yes, the kit covers pools up to 35,000 gallons, so a 20,000 gal pool is within the intended range.

Do I still need to use a cover?
Yes, a physical pool cover is recommended to prevent debris and reduce chemical loss during winter even when using this kit.

Is the shock included safe for vinyl liners?
The kit includes a chlorine-free floater for winter and pre-measured cal-hypo shock for sanitizing before closing; follow instructions to avoid prolonged direct contact with sensitive surfaces.