Metal Sequestrant Dose

Understanding Metal Sequestrants in Swimming Pools

Metal sequestrants help keep dissolved iron, copper, and other metals suspended in pool water so they are less likely to form stains or discolor the water. They do not remove metals from the pool. Instead, they bind with the metals and help keep them from depositing on pool surfaces.

Startup and Maintenance Doses

Startup or initial-treatment doses are usually larger because the product must bind with metals already present in the water. Maintenance doses are smaller and are added periodically because sequestrants slowly break down from chlorine, sunlight, and normal pool use.

When Sequestrant Is Helpful

• Filling a pool with well water or metal-containing source water.
• Managing known iron or copper in the pool.
• Following an ascorbic acid stain-removal treatment.
• Preventing stains after large water additions.
• Maintaining water with recurring metal problems.

Why Product Labels Matter

Sequestrants vary in strength and chemistry. Some are concentrated HEDP-based products, while others use different phosphonate blends. Always use the exact startup and maintenance rates listed on your product label.

Ongoing Metal Management

Because sequestrants degrade over time, pools with metal-containing fill water may need routine maintenance doses. Large water replacements, backwashing, leaks, and splash-out can also reduce the amount of active sequestrant in the water.