BioGuard SoftSwim Stain Control is a sequestrant formulated specifically for the biguanide chemistry of the SoftSwim program. It keeps dissolved iron, copper, and manganese locked in solution so they can’t settle out and stain pool surfaces — and it does a second job that matters just as much on a biguanide pool.
It helps maintain the presence of SoftSwim B and C. That’s not a minor footnote. Dissolved metals interfere with biguanide sanitizer and clarifier, quietly consuming them and shortening how long a residual holds. On a program where the sanitizer is the single most expensive recurring product, metals in the water are costing you money every week whether or not you ever see a stain.
There’s one requirement that’s easy to miss and expensive to skip: Stain Control must be used when starting a white plaster pool on SoftSwim B — whether metals are present or not. That’s not a recommendation scaled to your water test. It’s a condition of the start-up, and it applies to every white plaster SoftSwim pool.
Beyond that, it’s needed whenever metals are present in any pool type or in the make-up water, and at spring start-up and after any significant refill — the moments when new water brings new metal into the pool.
Dosing is keyed to a measured metal level rather than pool volume alone: 1 quart per 10,000 gallons controls up to 2 ppm of metals. Above 2 ppm you need proportionally more, plus a filter aid to physically remove what the sequestrant is holding.
Pro Tip: If you’re starting a white plaster pool on SoftSwim B, this product is required — metals test or not. BioGuard states it plainly, and the reason is that fresh white plaster is both the surface most likely to show staining and the one where a stain is hardest to remove. A start-up without Stain Control on a new plaster finish is the sort of shortcut that shows up as permanent discoloration on a brand-new surface, discovered weeks later when the only remaining options are a full stain protocol or an acid wash. Get the water tested by a dealer before start-up, add the Stain Control regardless of the result, and the finish stays clean.
Brand
BioGuard®
