green/black fungus on paving blocks

Hi there

had my back yard done in red paving blocks about a year ago I live near the sea and there is a build up of a greenish/black fungus type of growth between the blocks I can powerwash it off but can I treat it with anything to prevent it comming back?
cheers

You can use a fungicide when it is dry and then let it kill off the algae, powerwash and re-treat before sealing. Will make it much easier to maintain.

Kilsaran Lifestyle supply this type of product.

Heres a little hint.when ever you cook potatoes or rice(boil in the bag)in salty water.pour it on moss and fungus.its pretty dood.