Fence's green algae

Jestwasher.

Active ingredient is Benzalkonium Chloride - just buy it in an 5l container and dilute as instructed, works out cheaper than Wet & Forget.

ddac biocide aka soft wash will kill it off in about 48 hours.

Amazon - Spray & Leave, 5L £15.

BAC50 will get rid.

Dilute. Spray and leave.

If it's anything like wet and forget, it's 5 to 1.

40:1 in most situations.

I’ve seen people mention as high as 20:1

Some of our fences are almost completely green from algae. I quite like it, I appreciate it will reduce their lifespan, but they were put up in 1984 and still going strong. Apart from a few post that have been replaced from storm damage, the panels are fine.

Did my wood work in Winter with BAC 50, it's still clear.

when do you apply it ? summer it will dry instantly and out of summer washed off by rain in no time?