The other I have no idea- water doesn’t stick in those part pre cleaning and they don’t disappear. Could that be etched concrete I hear about?
Tannins I believe
Thank you! is the white spots also caused by tannins?
The bottom image
I found this thread through Google
Looks like this is a muriatic acid stain, bleach won’t take that out, they say it has to be stripped and coated or acid it more (uniformly/properly) than coat it. Thank god I documented the stains before running it over with the surface cleaner, if it becomes a problem it will be my insurance policy.