Patio Cleaning!

The patio has been down for nearly 20 years and is ok apart from the algae and black spots that have appeared over the years.
The algae can be got rid of with a pressure washer, and we do that every year around about this time but the black spots just aren't affected unless you blast the concrete away as well!

So, we've tried lots of different solutions in the past and Marlane suggested just using neat bleach.

Inserted are the before photographs, the larger photo is me spreading and scrubbing the neat, thick, bleach into the slabs for the third time but it seems to be working.

12 bottles of bleach so far but it is on offer at Morrisons and last week I got a load from Lidl when it was on offer there.