What does HTH Metal, Stain and Scale Control do?

HTH Metal, Stain and Scale Control prevents and treats metal staining and calcium scaling on pool surfaces and equipment. It sequesters dissolved metals like iron and copper so they cannot oxidize and leave stains, and it prevents hard water mineral deposits.

Why is my pool leaving brown or green stains on the walls?

Brown or orange staining usually indicates iron in the water; blue-green stains typically mean copper, often from algaecides or copper pipes. Add HTH Metal, Stain and Scale Control to sequester metals before they oxidize and deposit on surfaces. Also test and balance pH and alkalinity.

How do I treat metal stains in my pool using HTH Metal, Stain and Scale Control?

Do not shock the pool before treating metal stains—oxidizing metals with high chlorine worsens the staining. With chlorine at normal levels (1–4 ppm), lower pH slightly to 7.0–7.2, then add HTH Metal, Stain and Scale Control per the label dosage. Brush the stained areas thoroughly, run the filter continuously, and vacuum settled particles. Retest and balance chemistry after treatment.

How do I know if my pool has metal staining vs. algae staining?

Metal stains typically appear as brownish-orange (iron), blue-green (copper), or black (manganese) patches on pool surfaces and do not brush away easily. Algae stains are usually green, yellow, or black and are slippery or fuzzy to the touch. If a chlorine shock treatment removes the staining, it was likely algae. If staining remains or worsens after shocking, metals are the likely cause.

What causes copper or iron to get into pool water?

Common sources of pool metals include copper pipes or fittings corroded by low pH water, well water with naturally high iron content, some algaecide products that use copper as the active ingredient, and heat exchangers on pool heaters. Maintaining pH at 7.2–7.6 prevents acidic water from dissolving metals from equipment, and using HTH Metal, Stain and Scale Control sequesters metals before they can deposit.

How do I prevent scale buildup on pool surfaces and equipment?

Scale forms when calcium hardness is too high (above 400 ppm) combined with high pH and alkalinity. Prevent it by keeping calcium hardness between 200–400 ppm, pH at 7.2–7.6, and alkalinity at 80–120 ppm. Add HTH Metal, Stain and Scale Control monthly as a preventive treatment, especially in areas with hard fill water.

Can HTH Metal, Stain and Scale Control be used as a regular maintenance product?

Yes. In addition to treating active metal staining, HTH Metal, Stain and Scale Control can be used as a monthly preventive treatment to sequester dissolved metals and inhibit scale formation before they become visible problems. This is especially recommended for pools filled with hard well water or in areas with high mineral content.

Pool Stain Remover for Surface Stains and Scale Buildup

Name: HTH Pool Care Metal, Stain & Scale Control
Brand: HTH Pool
SKU: 67218
Availability: InStock

Product Benefits

Prevents Metal Stains

Stops dissolved metals from staining pool walls, floors, and fixtures for lasting clarity.

Protects Pool Equipment

Guards against mineral deposits and scale buildup that can damage filters, heaters, and pumps.

Prevents Cloudy Water

Keeps water sparkling and clear by reducing metal-induced discoloration and haze.

Remove Fresh Stains

Effectively lifts new metal and copper stains for visibly clearer pool surfaces.

How to Use

Why You Should Use This Product: This specialty treatment helps protect pool surfaces from metal staining and scale buildup. It prevents scale formation, helps control metals throughout the pool season, and can remove fresh metal and copper stains.

Before Use: Test pool water and ensure total alkalinity, pH, and calcium hardness are within recommended ranges.

Application Instructions

Add this product directly to the pool water with the circulation system running. Brush any undissolved particles to help disperse the product evenly. Keep water circulating and do not shock the pool for at least 8 hours after application.

Initial Treatment

Add 10 fl oz of this product per 10,000 gallons of pool water.

Maintenance Treatment

Add 2.5 fl oz of this product per 10,000 gallons of pool water weekly to help prevent stains and scale.

Opening Your Pool

Add 10 fl oz of this product per 10,000 gallons of pool water when opening or filling the pool. Do not shock the pool for 8 hours.

Closing Your Pool

Treat algae or cloudy water before adding this product. Add 10 fl oz of this product per 10,000 gallons of pool water. Keep water circulating for 24–48 hours before closing the pool for the season.

Ingredients

Active Ingredient:

Contains tetrasodium etidronate.

Safety, Storage, and Disposal

Safety

Use this product only as directed. Avoid contact with eyes, skin, and mucous membranes.

Wear protective eyewear and gloves when handling, and wash hands thoroughly after use.

Do not mix this product with other chemicals.

For complete safety information, warnings, and first aid instructions, refer to the product label.

First Aid

If product gets in eyes, rinse slowly and gently with water for 15–20 minutes and seek medical advice if irritation persists.

If on skin or clothing, remove contaminated clothing and rinse skin thoroughly with water.

If swallowed or inhaled, contact a poison control center or medical professional immediately.

Storage and Disposal

Keep product in its original, tightly closed container when not in use.

Store in a cool, well‑ventilated area away from heat and direct sunlight.

Use entire contents when possible. Triple rinse empty container and dispose in accordance with state and local regulations.

Do not reuse empty container.

For full storage, disposal, and emergency handling instructions, refer to the product label.

Frequently Asked Questions

What does HTH Metal, Stain and Scale Control do?

HTH Metal, Stain and Scale Control prevents and treats metal staining and calcium scaling on pool surfaces and equipment. It sequesters dissolved metals like iron and copper so they cannot oxidize and leave stains, and it prevents hard water mineral deposits.
Why is my pool leaving brown or green stains on the walls?

Brown or orange staining usually indicates iron in the water; blue-green stains typically mean copper, often from algaecides or copper pipes. Add HTH Metal, Stain and Scale Control to sequester metals before they oxidize and deposit on surfaces. Also test and balance pH and alkalinity.
How do I treat metal stains in my pool using HTH Metal, Stain and Scale Control?

Do not shock the pool before treating metal stains—oxidizing metals with high chlorine worsens the staining. With chlorine at normal levels (1–4 ppm), lower pH slightly to 7.0–7.2, then add HTH Metal, Stain and Scale Control per the label dosage. Brush the stained areas thoroughly, run the filter continuously, and vacuum settled particles. Retest and balance chemistry after treatment.
How do I know if my pool has metal staining vs. algae staining?

Metal stains typically appear as brownish-orange (iron), blue-green (copper), or black (manganese) patches on pool surfaces and do not brush away easily. Algae stains are usually green, yellow, or black and are slippery or fuzzy to the touch. If a chlorine shock treatment removes the staining, it was likely algae. If staining remains or worsens after shocking, metals are the likely cause.
What causes copper or iron to get into pool water?

Common sources of pool metals include copper pipes or fittings corroded by low pH water, well water with naturally high iron content, some algaecide products that use copper as the active ingredient, and heat exchangers on pool heaters. Maintaining pH at 7.2–7.6 prevents acidic water from dissolving metals from equipment, and using HTH Metal, Stain and Scale Control sequesters metals before they can deposit.
How do I prevent scale buildup on pool surfaces and equipment?

Scale forms when calcium hardness is too high (above 400 ppm) combined with high pH and alkalinity. Prevent it by keeping calcium hardness between 200–400 ppm, pH at 7.2–7.6, and alkalinity at 80–120 ppm. Add HTH Metal, Stain and Scale Control monthly as a preventive treatment, especially in areas with hard fill water.
Can HTH Metal, Stain and Scale Control be used as a regular maintenance product?

Yes. In addition to treating active metal staining, HTH Metal, Stain and Scale Control can be used as a monthly preventive treatment to sequester dissolved metals and inhibit scale formation before they become visible problems. This is especially recommended for pools filled with hard well water or in areas with high mineral content.

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Always read product label directions prior to using and use only as directed
Always add chemicals to pool water, never the other way around
Never add chemicals to pool water when people are in the pool
Never mix products together
Always store pool products in a cool, dry location and out of direct sunlight

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HTH Pool Care Metal, Stain & Scale Control