Cleaning old white stains from basement concrete

[Kansai]

I bought an older house from 1987 and the basement concrete floor has these stubborn white marks in patches. I don't want to seal or paint, just get the whitish powder off safely. Any recommendations for products or DIY methods that won't eat away at the concrete?

 

[schottperfecto99]

That white stuff is likely salt coming up from moisture in the concrete. I had the same problem in my garage. I used white vinegar mixed with warm water and scrubbed it with a stiff plastic brush. Then I rinsed it off and did it again where needed. Don't use metal brushes or strong cleaners as they can hurt the concrete. Try to keep the air moving down there so it doesn't come back.