The nice thing about today's rain in New York State...
is that it will make the weed pulling much easier tomorrow with the ground being soft.
There's a bright side to lousy weather. 
I managed to clean my composite deck with something called (I think) "30 second cleaner".
It's a concentrate that is probably mostly bleach that you mix 50/50 with water and apply with a pump sprayer.
I re-skinned by deck about 15(?) years ago with light brown TimberTech composite decking, and white composite railings.
Apparently, at the time, that material was first generation, and the white railings really hold mildew stains more than they should. so I have to clean the hell out of them every year so the mildew does not get out of control.
Some years, I have a company to come in and do it, but this year, money is tight (as it is for all of us), so instead of paying someone $200 to clean it, I did it myself with a $35 bottle of this cleaner.
Pic below. Left side is before cleaning, right side is after cleaning (this is an old pic).
You all have a nice day.
= new reply since forum marked as read
Seriously, the stuff works pretty good.
They market this cleaner as "no scrubbing required, but I have to scrub.
Spray onto a dry surface, let it sit, scrub it, rinse it off, repeat.
It's not a big deck, but it takes me three hours to clean the railings. The deck itself goes quickly.
It's never ending though! 
