F9 Efflo 4 LiterThis breakthrough in the restoration and cleaning industry is a user friendly, full 31. 45% strength muriatic acid replacement that works better with less harmful effects. Quickly remove efflorescence, calcium, calcium carbonate, and hard water stains on concrete, masonry, stucco, shingles, glass, synthetic stone, anodized aluminum, unpolished marble, and more. It can be used to etch concrete at stronger ratios or as a general cleaner at diluted