Roof Cleaning/Protection

[JaveaSteve]

Now that it’s stopped raining, (On Costa Blanca) this weekend is to be spent cleaning the water run off marks from the sides that appear to be worse than ever, possibly as a result of me using Meguiars One Step cleaner wax last month. Can I ask what others use/recommend/procedure for protecting the roof. 303 products, ceramic wax, ultimate polish?

 

[M-J]

I use a caravan/motorhome shampoo with an anti algae additive in, did the roof earlier in the year with it and the usual black streaks are far less than previous.