We have black spot algae appearing on the walls of

We have black spot algae appearing on the walls of our swimming pool. We understand that the best product to use is Lo Chlor black spot eradication but this doesn’t seem to be available in Italy. We are able to get it in the U.K. but know that it’s important to treat it asap. Does anyone have experience of this and know of a suitable product to remove it which is available in Italy? Many thanks