Fur on Cedar after power washing

My cedar deck is just over a year old.  Attempted to stain it last summer but weather and my schedule never agreed so I was only able to do the railings and about a 1/16 of the deck.  It was horribly filthy, and gray this summer and we were quoted $3000 for a stripping, power washing, light defuring, and staining.  I don't think so. I liked the guy that cost the most bu thought it try and tackle this myself.  I just used oxyclean a deck scrub brush and my wonderful power washer to clean the deck, which is did but now it has fur on it.  What's the best way to tackle this large area?  What sander?  Should I use 80 grit? I feel like that's too rough?  I read another post where you said sand, wait a month, then apply brightener.  Please advise how to best tackle the fur over a very large deck and the completed steps to beauty !