My house has a patio area outside the back door. The patio borders onto grass and makes a home for a pair of sheds. It doesn't drain well and is always in the shadow of the house, so that it stays damp long enough for algae to grow, leaving the area slimy and treacherous.
I clean the algae off the slabs when the weather is dry, but it grows back quickly as soon as it becomes damp again. Living in the UK, this is more often than is tolerable.
Long-term, I want to replace the entire area with something that drains properly and is dry enough to stop the growth completely. Until then, is there anything that can be done to inhibit the algae?