How to Use In The Swim Pool Winterizing and Closing Chemical Kit (Up to 15,000 Gallons): Complete 2026 Guide

TL;DR: The In The Swim Pool Winterizing and Closing Chemical Kit (Up to 15,000 Gallons) provides complete winterization with shock treatment, winterizing algaecide, and stain preventer. Application requires balancing water chemistry, shocking the pool, adding algaecide, adding winterizing chemicals, lowering water level, cleaning thoroughly, and installing a winter cover. The kit costs $45-$70 and protects pools through winter preventing algae growth, staining, and water quality degradation while ensuring easy spring opening.

SEO Summary: Comprehensive 2026 guide to using the In The Swim Pool Winterizing and Closing Chemical Kit covering kit contents, pre-winterization water balancing, shock treatment procedures, algaecide application, winterizing chemical addition, water level adjustment, pool cleaning, equipment winterization, and cover installation for pools up to 15,000 gallons.

Understanding the In The Swim Winterizing Kit

The In The Swim Pool Winterizing and Closing Chemical Kit (Up to 15,000 Gallons) is a comprehensive winterization solution designed to simplify pool closing while providing professional-quality protection. In The Swim, a trusted online pool supply retailer for over 30 years, formulated this kit to address all major winter water quality challenges in one convenient package. Rather than purchasing individual winterizing chemicals and calculating separate dosages, pool owners can use the In The Swim kit for complete, reliable winter protection with straightforward application procedures.

What's Included in the In The Swim Kit

The In The Swim Pool Winterizing and Closing Chemical Kit contains three essential winterizing products carefully selected to work together for optimal protection. In The Swim Chlorine Shock (calcium hypochlorite) eliminates bacteria and oxidizes organic contaminants before winter. In The Swim Winterizing Algaecide provides concentrated, long-lasting algae prevention effective for 3 to 6 months even in dormant pools. In The Swim Stain and Scale Preventer sequesters metals and minerals preventing surface staining and scaling during dormancy. Each product is clearly labeled with dosage instructions for pools up to 15,000 gallons, eliminating calculation errors and ensuring proper application.

Why Choose the In The Swim Winterizing Kit

The In The Swim kit offers several advantages for pool winterization including complete protection addressing algae, bacteria, staining, and scaling in one package, simplified purchasing (all necessary chemicals together versus buying separately), proven formulations from a trusted 30+ year pool supply company, cost-effectiveness ($45-$70 for complete kit versus $70-$100 for individual products), and clear instructions specific to In The Swim products ensuring proper use. For pool owners seeking reliable winterization without the complexity of multiple product selection and dosage calculations, the In The Swim kit provides an ideal solution.

Ideal Pool Types and Sizes

The In The Swim Pool Winterizing and Closing Chemical Kit is formulated for all pool types (vinyl liner, fiberglass, concrete/plaster) and all sanitizer systems (chlorine, bromine, salt water) up to 15,000 gallons. This includes most above-ground pools (12 to 24 feet diameter), smaller in-ground pools (12x24 feet or smaller), and vinyl liner pools of appropriate size. For larger pools (15,000 to 30,000 gallons), use two In The Swim kits or consider larger winterization products like Winter Care Pool Closing Kit for pools up to 20K gallons.

Step 1: Balance Pool Water Chemistry

Proper water chemistry before adding In The Swim products ensures maximum effectiveness and optimal winter protection.

Complete Water Testing

Test all water chemistry parameters using a quality test kit like the Taylor K-2005 Complete Test Kit. Test pH (target 7.4 to 7.6 before winterization), total alkalinity (target 80 to 120 ppm), calcium hardness (target 200 to 400 ppm for concrete pools, 150 to 250 ppm for vinyl pools), and current chlorine level (should be 1 to 3 ppm before adding winterizing chemicals). Record all results to track adjustments needed and document pre-winter chemistry.

Adjust Total Alkalinity First

Balance total alkalinity to 80 to 120 ppm before adjusting other parameters. Alkalinity buffers pH and prevents rapid pH swings during winter. Add alkalinity increaser (sodium bicarbonate) if levels are low. If alkalinity is high, lower it by adding muriatic acid or pH decreaser in small increments. Allow 4 to 6 hours circulation between adjustments and retest to confirm proper levels before proceeding.

Adjust pH to Optimal Range

After alkalinity is balanced, adjust pH to 7.4 to 7.6. This range prevents corrosion (low pH) and scaling (high pH) during winter dormancy and ensures In The Swim algaecide works effectively. Add pH increaser (soda ash) if pH is below 7.4, or pH decreaser (dry acid) if above 7.6. Make small adjustments, circulate for 4 to 6 hours, and retest before making additional changes.

Verify Calcium Hardness

Ensure calcium hardness is in proper range: 200 to 400 ppm for concrete/plaster pools, 150 to 250 ppm for vinyl liner pools. Add calcium hardness increaser if levels are below target range. Proper calcium levels prevent water from becoming aggressive and etching pool surfaces during winter. Most pools have adequate calcium from fill water, but soft water areas may require calcium addition.

Step 2: Shock the Pool

The In The Swim Chlorine Shock eliminates bacteria and oxidizes organic contaminants before winter.

Pre-Shock Preparation

Ensure the pool pump and filter are operating properly before shocking. Clean or backwash the filter to ensure proper circulation. Remove any large debris from the pool that could interfere with shock distribution. Plan to shock in the evening or on a cloudy day to minimize UV degradation of chlorine.

Dissolve and Apply In The Swim Shock

The In The Swim kit includes calcium hypochlorite shock, a powerful oxidizer that should be pre-dissolved for even distribution. Fill a 5-gallon bucket with pool water (never add water to shock, always add shock to water). Slowly add the In The Swim Chlorine Shock to the bucket while stirring. Stir until completely dissolved. The solution will be cloudy and may generate heat, this is normal. With the pump running, slowly pour the dissolved shock solution around the pool perimeter. Distribute evenly to prevent concentrated areas. Pour near return jets for rapid distribution.

Dosage for 15,000 Gallons

The In The Swim shock is pre-measured for pools up to 15,000 gallons, use the entire package for optimal bacteria elimination and organic contaminant oxidation. This dosage raises chlorine to 10 to 15 ppm, providing thorough oxidation and complete bacteria elimination. For pools significantly smaller than 15,000 gallons, adjust dosage proportionally or consider smaller winterization kits.

Circulation After Shocking

Run the pump continuously for 8 to 12 hours after adding In The Swim Chlorine Shock to circulate the product throughout the pool. This extended circulation ensures complete distribution through all 15,000 gallons and allows the shock to oxidize contaminants effectively. Wait 24 to 48 hours after shocking before proceeding to the next step, this allows chlorine levels to drop from shock levels (10 to 15 ppm) to safer levels (3 to 5 ppm).

Step 3: Add In The Swim Winterizing Algaecide

The In The Swim Winterizing Algaecide provides long-lasting algae prevention throughout winter dormancy.

Application Timing

Add In The Swim Winterizing Algaecide 24 to 48 hours after shocking, once chlorine levels have dropped to 3 to 5 ppm. Test chlorine to confirm it's in this range before proceeding. High chlorine can reduce algaecide effectiveness, so proper timing is critical for optimal protection.

In The Swim Algaecide Application

With the pool pump running, slowly pour the In The Swim Winterizing Algaecide around the pool perimeter. Walk around the entire pool edge, distributing the product evenly. Pour near return jets when possible, the jet flow helps distribute the algaecide quickly throughout the pool. The In The Swim algaecide is pre-measured for pools up to 15,000 gallons, so use the entire bottle for optimal protection. The concentrated formula provides 3 to 6 months of algae prevention even in dormant pools.

Circulation After Algaecide

Run the pool pump for 4 to 8 hours after adding In The Swim Winterizing Algaecide to ensure even distribution throughout the pool and all plumbing lines. This circulation time allows the algaecide to reach all areas of the pool including corners, steps, and plumbing where algae might otherwise establish during winter. For additional algae protection, consider supplementing with products like Omni Winter Care Algaecide.

Step 4: Add In The Swim Winterizing Chemicals

The In The Swim Stain and Scale Preventer protects pool surfaces from mineral deposits and metal staining.

Application Method

With the pump running, pour the In The Swim Stain and Scale Preventer around the pool perimeter. Distribute evenly, walking around the entire pool edge. The product is pre-measured for pools up to 15,000 gallons, use the entire bottle. The stain and scale preventer contains sequestering agents that bind to metals (iron, copper, manganese) and minerals (calcium, magnesium) in solution, preventing them from precipitating onto pool surfaces and causing stains or scale during winter.

Final Circulation Period

Run the pump for 4 to 8 hours after adding In The Swim Stain and Scale Preventer to ensure complete distribution throughout the pool and all plumbing. This final circulation period allows all three In The Swim products (shock, algaecide, stain preventer) to work together, creating comprehensive winter protection. For best results, run the pump overnight (8 to 12 hours total) to ensure thorough mixing and distribution.

Post-Application Water Testing

After all In The Swim products have circulated for 8 to 12 hours, test water chemistry one final time. Check pH (should remain 7.4 to 7.6), total alkalinity (should remain 80 to 120 ppm), and chlorine level (should be 3 to 5 ppm). The In The Swim products are formulated to have minimal impact on balanced water chemistry, but testing confirms this and identifies any final adjustments needed.

Step 5: Lower Water Level

Proper water level prevents freeze damage to skimmers and return lines while maintaining adequate water for pool structure support.

Determine Target Water Level

Lower water to 4 to 6 inches below the skimmer opening for in-ground pools. For above-ground pools, follow manufacturer specifications, typically 3 to 4 inches below the skimmer. This level prevents water from entering skimmer and return lines where it could freeze and cause damage. Never drain pools completely, water weight is necessary to prevent pool structure damage from ground pressure.

Water Removal Method

Use a submersible pump to lower water level efficiently. Place the pump in the deep end and discharge water away from the pool area to prevent soil saturation. Alternatively, use the pool's waste setting on the multiport valve if equipped, though this is slower than a submersible pump. Monitor water level carefully to avoid lowering too much.

Timing Considerations

Lower water level after all In The Swim chemicals have circulated for 8 to 12 hours. This ensures chemicals are distributed throughout the pool at full water volume before level is reduced. If rain is forecast, wait until after lowering water level to avoid dilution of winterizing chemicals.

Step 6: Clean Pool Thoroughly

Thorough cleaning after adding In The Swim chemicals removes debris and ensures the pool is pristine before covering.

Brush All Pool Surfaces

Brush all pool surfaces thoroughly including walls, floor, steps, benches, and corners. Use a brush appropriate for your pool surface, nylon bristles for vinyl liners, stainless steel for concrete or plaster. Use quality brushes like the Swimline H2O Pro Pool Brush or HydroTools Pool Floor and Wall Brush. Brushing dislodges any remaining algae spores or biofilm that vacuuming alone might miss.

Vacuum Pool Bottom

Vacuum the entire pool floor, steps, and benches to remove settled debris and dirt. Use a manual vacuum or automatic pool cleaner like the XtremepowerUS Automatic Pool Cleaner. Vacuum to waste if possible to remove debris from the pool entirely rather than sending it through the filter. If vacuuming through the filter, clean or backwash the filter immediately after vacuuming.

Skim and Remove Final Debris

Use a pool skimmer to remove any final floating debris from the surface. Empty skimmer and pump baskets one last time. Remove all pool toys, floats, and accessories. Clean these items and store them indoors to prevent weather damage and deterioration.

Step 7: Winterize Equipment and Install Cover

Equipment winterization and cover installation complete the pool protection process.

Winterize Pool Equipment

Drain pump, filter, and heater completely by removing drain plugs and allowing all water to drain. Blow out plumbing lines with compressed air or shop vacuum to remove residual water. Install winterizing plugs like winterizing test plugs in all lines after blowing them out. Install Gizzmos (expansion plugs) in skimmers to absorb ice expansion and protect skimmer throats from cracking. Add pool antifreeze to lines that can't be completely drained. Store drain plugs in pump basket so they're not lost.

Install Winter Cover

Install a quality winter cover appropriate for your pool type. Solid safety covers provide maximum protection and last 10 to 15 years. Mesh safety covers allow drainage and last 12 to 15 years. Standard winter covers are economical but require cover pumps. Clean the cover if previously used, then spread it evenly over the pool ensuring it extends beyond the pool edge on all sides.

Secure Cover Properly

For safety covers, attach springs to deck anchors working around the pool systematically to ensure even tension. For standard covers, secure with water bags filled 2/3 full and spaced 2 to 3 feet apart around the perimeter. Use double bags at corners for extra security. Never use concrete blocks or hard objects that can damage covers.

Air Pillow for Above-Ground Pools

For above-ground pools, install an air pillow like the 4' winterizing air pillow before installing the cover. Inflate to 60 to 70% capacity and secure with light rope. The pillow creates a peak that sheds water and debris while absorbing ice expansion pressure to protect pool walls.

Cover Pump Installation

If using a solid cover, place an automatic cover pump on the cover to remove accumulated water. Position the pump in the lowest point where water naturally collects. Ensure the discharge hose directs water away from the pool area. Check the pump periodically throughout winter to ensure it's operating properly.

Conclusion

The In The Swim Pool Winterizing and Closing Chemical Kit (Up to 15,000 Gallons) provides comprehensive, professional-quality winterization in a convenient, cost-effective package. By following the seven-step process outlined in this guide (water chemistry balancing, shock treatment, algaecide application, winterizing chemical addition, water level lowering, thorough cleaning, and equipment winterization with cover installation), pool owners ensure their pools receive optimal winter protection preventing algae growth, surface staining, scaling, and water quality degradation through months of dormancy.

The In The Swim brand's 30+ years of pool supply expertise is evident in the kit's carefully selected products that work together seamlessly. The chlorine shock eliminates bacteria and oxidizes organic contaminants for clean starting water. The winterizing algaecide prevents algae growth even in dormant pools exposed to some sunlight through mesh covers. The stain and scale preventer sequesters metals and minerals preventing staining and scaling. Together, these three products create comprehensive protection that keeps pools in excellent condition throughout winter.

The investment in the In The Swim Pool Winterizing and Closing Chemical Kit ($45 to $70) delivers exceptional value compared to purchasing individual winterizing chemicals ($70 to $100) while providing the convenience of having all necessary products in one package. The systematic application process (balance, shock, algaecide, winterizing chemicals, lower level, clean, winterize equipment, cover) takes just a few hours spread over 2 to 3 days but provides months of protection. Pools winterized with the In The Swim kit open in spring with clear water, clean surfaces, and balanced chemistry, requiring minimal cleanup and chemical adjustment before swimming can begin.

As you prepare your pool for winter 2026, trust the In The Swim Pool Winterizing and Closing Chemical Kit to provide the reliable, comprehensive protection your pool deserves. Whether you're a first-time pool owner winterizing for the first time or an experienced pool enthusiast seeking simplified winterization, the In The Swim kit delivers professional-quality results with consumer-friendly convenience. Your investment in proper winterization with In The Swim products ensures your pool survives winter in excellent condition and opens smoothly when warm weather returns, ready for another season of swimming enjoyment.

Key Takeaways:

• In The Swim Pool Winterizing Kit provides complete winterization for pools up to 15,000 gallons at $45 to $70
• Kit includes In The Swim Chlorine Shock, Winterizing Algaecide, and Stain and Scale Preventer
• Pre-winterization chemistry balancing (pH 7.4 to 7.6, alkalinity 80 to 120 ppm) ensures maximum product effectiveness
• Shock treatment raises chlorine to 10 to 15 ppm for complete bacteria elimination and organic contaminant oxidation
• Wait 24 to 48 hours between shocking and adding algaecide to allow chlorine to drop to 3 to 5 ppm
• All In The Swim products are pre-measured for pools up to 15,000 gallons, use entire bottles for optimal protection
• Run pump 4 to 8 hours after each chemical addition to ensure complete distribution throughout pool and plumbing
• Lower water level 4 to 6 inches below skimmer to prevent freeze damage to plumbing and equipment
• Complete equipment winterization includes draining equipment, blowing out lines, installing plugs, and adding antifreeze
• Quality winter cover protects pool from debris and weather while In The Swim chemicals maintain water quality

Winterize your pool successfully with the In The Swim Pool Winterizing and Closing Chemical Kit and maintain optimal water chemistry with quality pool chemicals. Test water accurately using reliable test kits and maintain your pool year-round with comprehensive maintenance kits. Your investment in proper winterization with In The Swim products ensures your pool remains protected and ready for enjoyment when swimming season returns.