What is a good solution to remove algea from a fence

Power washing does it really well. We did it to remove the green from our pergola and were shocked at how much better it looked.

Agreed, definitely rent (or borrow) a power washer, it will make ALL of the difference! Wait a day or two before it is completely dry before staining and finishing.

round up or bleach

I had to do this earlier in the year and I tried a couple of differen solutions. In the end I scrubbed it with warm water and dish soap and then rinsed well. When dry the fence is ready to stain or paint. This is quite hard work, but makes a great job.

Spray solution of algacide & scrubby off with softer brush?