Fence Algae

About a decade ago I replaced the flimsy fence panels that were in my garden after I found my black lab barking at my neighbors through their patio door after a but of a storm.

I got a fairly decent looking pressure treated hit and miss panel from a local sawmill

i think this is it

for years I used ronseal harvest gold big tubs of fence paint, I honestly can't remember the exact name, 5 year or something, they don't seem to do the exact tubs anymore.

Two years ago I moved to a light blue ronseal fence life plus

ronseal fence life plus

So, I don't know whether it is the general age of the fence or the change of colour, but our north facing fences show signs of what I think is algae not long after painting.

I painted summer 2024, and there was algae by this time of year,

I painted again this summer, I was looking out my kitchen window and there is plenty of algae.

I am reading that Bondex seems to be a bit better than ronseal, but, has that ship sailed? Do I need to do some treatment to get rid of the algae in between? I'm not arsed with a lot of faff, I would prefer something that could both deal with the algae and stain the wood in one go, but if it was something that would last a few years I would do a separate treatment and colour.

Has anyone any experience on this?