BioGuard Pool Magnet Plus | Metal Stain Preventer

BioGuard Pool Magnet Plus is a concentrated sequestrant that locks iron, copper, and manganese in solution so they can't stain your pool. It also eliminates discolored water caused by dissolved metals — the brown, green, or tea-colored tint that shows up when metal-laden fill water meets chlorine. Metal staining is one of the more discouraging problems in pool ownership because it looks like permanent surface damage. What's actually happened is that dissolved metal — from well water, a corroding heater or fitting, or the municipal supply — came out of solution and deposited on the finish. The usual trigger is chlorination: raising the chlorine level oxidizes dissolved metals and drops them onto whatever they land on. That's why stains so reliably appear right after opening or right after a shock treatment, seemingly from nowhere. A sequestrant intervenes ahead of that reaction. Its molecules bind the metal and hold it chemically unavailable, so chlorine can't precipitate it. The metal stays dissolved and harmless, circulating with the water rather than depositing on it. The formula has been recently reformulated and is more concentrated and effective than the version it replaced. It stays effective for three to four weeks, which is why monthly application covers the interval — pool professionals recommend monthly use in any pool filled with iron-containing water. It also removes fresh metal stains, at a heavier dose scaled to how bad the staining is. And BioGuard specifically recommends pairing it with a filter aid: the sequestrant holds the metal in suspension, and the filter aid gives your filter the ability to actually capture and remove it. Sequestering alone manages the metal; sequestering plus filtration gets it out of the pool. Pro Tip: Add this before you chlorinate a fresh fill, not after you see a stain. Chlorine is a powerful oxidizer, and raising the chlorine level is precisely what knocks dissolved iron and copper out of solution and onto your pool surface. The metal was in the water the whole time — invisible and harmless — until something precipitated it. If you're filling from a well, or topping off substantially, dose the sequestrant first and let it circulate before adding sanitizer. Five minutes of sequence discipline prevents a stain that costs a multi-step protocol and several products to remove. Brand BioGuard®