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Poly-Guard® Liquid, Scale & Rust Preventer
  • Poly-Guard® Liquid, Scale & Rust Preventer
  • Poly-Guard® Liquid, Scale & Rust Preventer
  • Poly-Guard® Liquid, Scale & Rust Preventer
Poly-Guard® Liquid, Scale & Rust Preventer

Poly-Guard®

Poly-Guard® Liquid, Scale & Rust Preventer

SKU:  GL41N
SKU:  GL41N
Size

Liquid Hardness and Corrosion Control Concentrate

  • Economical way to treat hard water and iron without a water softener
  • Forms protective coating on plumbing and heating surfaces exposed to water
  • Controlled, consistent polyphosphate release protects equipment by preventing hard water scale and iron buildup in hot water heaters, ice machines, coffee machines, dishwashers, beverage dispensers and more
  • Refillable cartridge is compatible with standard #10 filter housings, treats up to 30,000 gallons
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A Cost-Effective Alternative for Soft Water

Poly-Guard Liquid gives you a flexible, cost-effective way to control hardness, iron, and corrosion—without installing a full water softener system. It’s an ideal solution for protecting equipment and plumbing in applications where space, budget, or system design limit traditional softening options.

Protect Equipment and Reduce Callbacks

From water heaters to ice machines, Poly-Guard helps extend equipment life and maintain performance—reducing scale buildup, service issues, and costly repairs for your customers.

WHY CONTRACTORS RELY ON POLY-GUARD LIQUID

ECONOMICAL HARDNESS CONTROL - Treats hard water and iron without the need for a full softener system—ideal for targeted applications

PREVENTS SCALE + CORROSION - Forms a protective coating on plumbing and heating surfaces to reduce buildup and system wear

PROTECTS CRITICAL EQUIPMENT - Helps keep water heaters, ice machines, dishwashers, and beverage equipment running efficiently

CONSISTENT POLYPHOSPHATE DELIVERY - Controlled release helps prevent hard water scale and iron buildup over time

FLEXIBLE INSTALLATION OPTIONS - Compatible with chemical feed pumps or refillable cartridge systems for #10 filter housings

HIGH CAPACITY PERFORMANCE - Refillable cartridge treats up to 30,000 gallons—ideal for ongoing protection with predictable service intervals

TRUSTED + CERTIFIED - NSF/ANSI/CAN 60 certified for safe use in potable water systems

Build A More Versatile Water Treatment Offering

Poly-Guard Liquid allows you to tailor solutions to the job—whether you’re protecting a single appliance or an entire system—while keeping installs simple and cost-effective.

Use Poly-Guard Liquid to deliver dependable scale and corrosion control—without the need for a full softening system.

INSTRUCTIONS FOR USE (Read entire product label before using):

Inject Poly-Guard® by chemical feed pump into the raw water system as close to the source as possible.

Poly-Guard is normally fed at a rate of 1 gal. per 200,000 gal. of water (2.5 ppm of phosphate). In case of above-normal iron and corrosion, increase feed rate to 1 gal. per 100,000 gal. of water (5 ppm).

Follow procedures for injecting Poly-Guard into water system as specified by the chemical feed pump manufacturer or supplier. Poly-Guard is compatible with most chemical feed pumps. Contact your local Poly-Guard distributor or visit www.proproducts.com for more details.

This product is NSF Certified to meet NSF/ANSI/CAN 60 Standard for drinking water additives. Blended phosphates, maximum use level for potable water: 30 mg/L.

Product Resources

DOSAGE CALCULATOR: Poly-Guard
Scale & Rust Preventer, Liquid
Resource: SDS Sheet English
Resource: SDS Sheet French

SKU Detail

SKU
GL41N GL05N
Size 1 gal. 5 gal.
Item UPC 818125000689 818125001617
Item Length 6 in 12 in
Item Width 6 in 12 in
Item Height 12 in 14.75 in
Item Weight 8.9 lb 61.9 lb
Case Pack 4 1
Case UPC 10018125002684
Case Length 12.38 in 12 in
Case Width 12.38 in 12 in
Case Height 12.28 in 14.75 in
Case Weight 36.55 lb 45.65 lb
Cases/Pallet 48 36
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Note: Specifications are subject to change.

Customer Reviews

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Frequently Asked Questions

Pro Products

Poly-Guard® Liquid is a phosphate-based treatment used to prevent scale, corrosion, rust staining, and copper leaching in potable water systems. It is typically injected into the water supply using a chemical feed pump and is commonly used by contractors in residential, commercial, and industrial applications.
Poly-Guard® Liquid prevents hard water stains by forming a protective barrier that reduces scale and mineral deposits on plumbing, fixtures, and equipment. It is especially useful in systems where water leaves visible white scale or iron staining on surfaces.
Poly-Guard® Liquid prevents scale formation by interfering with calcium and mineral crystallization before buildup occurs. It is best used when water conditions are causing visible scale on fixtures, pipes, or equipment.
Poly-Guard® Liquid is applied through a chemical feed pump into the raw water system, ideally as close to the water source as possible. The product directions also state that the injection procedure should follow the chemical feed pump manufacturer’s or supplier’s guidance.
The normal feed rate is 1 gallon of Poly-Guard® per 200,000 gallons of water. In water supplies with above-normal iron and corrosion conditions, the feed rate should increase to 1 gallon per 100,000 gallons. For best results, dosage should be confirmed based on the specific application.
Yes. Poly-Guard® Liquid is formulated to help protect metal and plastic surfaces from corrosion and copper leaching, while also helping shield pumping pipes and fixtures from calcium and scale buildup. That makes it relevant for both stain prevention and longer-term system protection.
Poly-Guard® Liquid is formulated for potable water applications and is certified to meet NSF/ANSI/CAN Standard 60 for drinking water additives. That certification helps support its use in residential, commercial, and industrial drinking water systems when it is applied as directed.
No. Poly-Guard® Liquid is a treatment additive used to help prevent staining, scale, and corrosion in a water system, but it is not the same thing as a whole-home filter or a water softener. It is often part of a broader treatment approach for hard water, iron staining, or corrosion control.
Yes. The product is specifically described as helping prevent iron staining as well as hard water scale stains. Public water-treatment guidance also supports the use of phosphate-based treatments to help control aesthetic issues related to iron, manganese, and hardness in potable water systems.
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