I know Ill get bashed, but I pressure wash all my properties atleast once a year. I was spending a ton of $$$$ on bleach. So I tried this http://www.homedepot.com/p/ZEP-128-o...S128/202056507
and haven't use bleach since. I mix it in a 5 gallon bucket and use a nice soft brush too scrub, and most of the time I don't need to even pressure wash, which is real nice for me, since Im the one who has to do the painting also.