Protecting my shed from the elements?

[Hightowermark]

Hi i build a shed last year and used treated wood for everything (frame and shiplap). I also painted a clear protective stain on it aswell, it was a little thin. Now after our nice weather th3 wood has a few greenish marks on it, now i know i need to protect it more.

Now the question is is there anything i can use to remove this green ish stuff and what are the best things now to protect it?

Thanks

 

[Thermo]

probably a surface mould, try giving it a wipe off with a damp cloth.