We have extremely hard water in our area. The sprinkler overspray mixes with the local red dirt and creates very nasty stains on concrete. We use a product with hydrofluoric and hydrochloric acid on other surfaces, but it is not meant for concrete. The stains are from the dissolved solids in the water drying on the concrete. Does anyone know how to get this stuff off? It is very tenacious stuff.

I've always used HF acid to remove hard water stains.

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