What works for most pool tile stains?

A pumice stone works for most pool tile stains, but only on ceramic or porcelain tile — not on glass, metal, or painted surfaces. It’s cheap, lasts forever, and removes calcium scale and hard water stains without scratching glazed tile. Wet the stone and tile, then scrub gently. For organic buildup, use a dedicated pool tile cleaner or stiff nylon brush instead.