It was some sort of plant food that leaked all over the tiles. Pressure washing made almost no difference.
paint them?
I think thats the best option.
concrete cleaner?
In conjuction with your jet wash, use some undiluted bleach.
Use a hard scrubbing type brush to work the bleach into the concrete agitate it and then jet wash it.
I had the same on my patio a few months ago and it came out spotless…
I’d def try concrete cleaner first, wait until it cools down though and pour a decent amount. Likely you’ll need to scrub it so be careful of contact/getting in your eyes. If you’re bothered then get some paving seal afterwards and roll on to prevent further staining.
I used Comma Hyperclean in the past to remove oil stains from some paving and it made the patch I cleaned look like new. Problem was that area was cleaner than everything else.
Stain it with something else
Ammonia
Coke or Pepsi.
brick acid
Use a nuke, it never fails
^ May have unintended second-order consequences
Brick acid is probably your best bet unless you can just flip them
They aren’t actually tiles. It is a concrete floor with lines drawn onto it.
Ouzo.
Sorry thought we were naming favourite drinks