BioGuard Pool Closing Complete | Pool Winterizer

• 1 x BioGuard Pool Closing Complete bottle, in your selected size
• Full manufacturer label with dosing rates, application directions, and safety information

Available in 72 oz. and 2 Liters. Both sizes treat up to 25,000 gallons per bottle.

Concentrated 3-in-1 Closing Formula

Clarifies water, prevents waterline buildup, and removes phosphates from a single bottle. Three separate closing tasks handled in one application instead of three products applied in sequence.

Formulated for Cold Water Temperatures

Engineered to perform in the temperature range a closed pool actually sits in through the off-season, rather than being a summer product pressed into winter service.

Removes Phosphates

Strips out the primary nutrient algae relies on, so the water going under the cover has substantially less to feed on during the months when no sanitizer residual will be maintained.

Controls Waterline Buildup

Targets the oils and organic residue that form the scum ring at the waterline. Left alone over a winter, that ring hardens into the most stubborn cleanup task of the entire opening process.

Protects Surfaces and Equipment

Helps guard pool surfaces and any equipment in contact with the water against scale formation and corrosion through the cold weather months, when nothing is circulating to keep minerals in suspension.

Saves Time at Spring Opening

Every one of these effects compounds over five or six idle months. A pool closed properly opens clearer, needs less shock, and costs less to bring back into service than one that was simply covered.

Pairs with BioGuard Arctic Blue Winter Kits

Designed as the finishing step alongside the Arctic Blue closing program, which supplies the winter shock and algae protection. This product completes that routine rather than duplicating it.

Works in Every Pool Type

Suitable for plaster, gunite, vinyl liner, fiberglass, and painted surfaces, in-ground and above-ground alike.

Pool Closing Complete is a concentrated liquid blend, and each of its three functions works through a different mechanism.

Clarification addresses particles too fine for a filter to capture. Most of the haze in a pool that tests fine is suspended material measured in fractions of a micron — small enough to pass straight through a sand bed or cartridge and recirculate indefinitely. Clarifying agents cause those particles to gather into larger masses that either settle to the floor or become large enough for the filter to remove during the final hours of circulation before closing.

Waterline protection targets the oils and organic residue that concentrate at the surface. Body oils, sunscreen, lotions, and airborne pollutants float, so they collect in a narrow band right at the water's edge and bond to tile, vinyl, and plaster. Over a stagnant winter that band dries, hardens, and cements itself in place. Treating it before closing keeps the residue mobilized and prevents the ring from setting.

Phosphate removal is the function with the longest reach. Phosphates are dissolved nutrients — they aren't visible, they don't affect clarity directly, and no amount of sanitizer destroys them. What they do is feed algae. During swim season a maintained chlorine residual holds algae back regardless of how much food is available, so the phosphate level often goes unnoticed. Under a winter cover, with no residual and no circulation, that protection is gone and the nutrients are still there. Removing phosphates at closing takes the food away before the guard comes down.

It's worth being clear about what this product is not. Pool Closing Complete is not a sanitizer, not a shock, and not an algaecide. It contains no chlorine and kills nothing. It's a water conditioner that prepares the water chemistry for a long idle period, and it's designed to be used alongside a winter shock and algaecide — not in place of them.

Pro Tip: Order of operations matters, and this product goes last. Balance the water first, then apply your winter shock and let it circulate, then your winterizing algaecide, and only then Pool Closing Complete — followed by two hours of circulation before you close everything down. Adding a clarifier before the shock has finished working means it spends itself gathering material the shock is still breaking apart. Timing matters too: close when water temperature is consistently below about 60°F. Closing a warm pool leaves it warm enough under the cover for algae to keep growing on whatever nutrients remain, which undoes much of what a careful closing was meant to accomplish.

Dosage Reference

• Pools up to 25,000 gallons: apply the entire bottle
• Pools under 12,000 gallons: apply half the bottle

Before Applying

1. Confirm all pool equipment is operating properly, including the pump, filter, skimmer, and heater.
2. Backwash and/or clean the filter if needed, following your equipment manufacturer's directions.
3. Balance the water — correct total alkalinity, pH, and calcium hardness before closing.
4. Complete the earlier steps of your closing routine, including winter shock and winterizing algaecide, allowing each to circulate per its own label.
5. Follow your equipment manufacturer's directions for winterizing pumps, heaters, and plumbing.

Application

1. Shake the bottle well before using.
2. Apply the correct amount for your pool volume using the dosage reference above.
3. Pour slowly and directly into the water while walking around the deep end of the pool.
4. Allow the pump and filter to operate for at least 2 hours after application.
5. Complete your remaining closing steps and install the winter cover.

Closing Sequence

For best results, apply closing products in this order, letting each circulate before moving to the next:

1. Balance the water — total alkalinity, then pH, then calcium hardness
2. Clean the pool thoroughly, including brushing the waterline
3. Apply winter shock and circulate per its label
4. Apply winterizing algaecide and circulate per its label
5. Apply Pool Closing Complete and circulate at least 2 hours
6. Lower the water level as required for your cover type, winterize equipment and plumbing, and install the cover

Storage and Handling

• Store in a cool, dry, well-ventilated area, out of direct sunlight and protected from freezing
• Keep the container tightly closed and clearly labeled
• Store separately from sanitizers, acids, and oxidizers
• Keep out of reach of children and pets
• Read and follow all label precautions, first aid, and disposal directions before use

Pro Tip: Brush the waterline before you apply this, not after. A stiff brush run around the tile and the top few inches of the wall breaks the existing scum band loose so the product can carry it away, rather than sealing a hardened ring in place for the winter. Take the extra ten minutes on the skimmer basket and pump basket too — organic debris left in either one spends the off-season decomposing into exactly the material you just paid to remove from the water.

• Brand: BioGuard
• Product Type: Pool closing and winterizing water conditioner
• Form: Liquid concentrate
• Available Sizes: 72 oz. and 2 Liters
• Functions: Clarifier, waterline buildup preventative, and phosphate remover
• Coverage: Up to 25,000 gallons per bottle
• Small Pool Dose: Half bottle for pools under 12,000 gallons
• Circulation After Application: Minimum 2 hours
• Application Method: Pour slowly into the water while walking the deep end
• Formulated For: Cold water temperatures and extended off-season idle periods
• Chlorine Content: None
• Bromine Content: None
• Suitable Surfaces: Plaster, gunite, vinyl liner, fiberglass, painted
• Sanitizer Compatibility: Chlorine, bromine, salt generator, and mineral system pools
• Companion Products: BioGuard Arctic Blue Winter Kits
• Not A Substitute For: Winter shock, winterizing algaecide, or water balancing
• Shipping Classification: DOT-regulated — ground shipping only

Pool Types and Surfaces

• In-ground and above-ground pools
• Plaster and gunite
• Vinyl liner
• Fiberglass
• Painted surfaces

Sanitizer Programs

• Chlorine pools — fully compatible
• Bromine pools — fully compatible
• Salt chlorine generator pools — fully compatible; follow your generator manufacturer's winterizing instructions for the cell itself
• Mineral system pools — fully compatible

Works Alongside

• BioGuard Arctic Blue Winter Kits — designed as the finishing step of that closing program
• Winter shock products, applied before this product
• Winterizing algaecides, applied before this product
• Winter pool covers of all types, including solid, mesh, and safety covers

What It Does Not Do

• Not a sanitizer. Contains no chlorine or bromine and provides no disinfection. Your closing routine still needs a winter shock.
• Not an algaecide. It removes the nutrient algae feeds on, but it does not kill algae. A winterizing algaecide is still required.
• Not a substitute for water balance. Total alkalinity, pH, and calcium hardness should all be corrected before closing. Unbalanced water sitting idle for months is how surfaces get etched and equipment corrodes.

Important Handling Cautions

• Never mix with other chemicals. Add each closing product separately, allowing circulation between applications.
• Not intended for oral consumption.
• Shake the bottle well before use — the concentrate settles.