I do understand that whatever is on there, if anything, needs to be stripped to a blank slate. In my mind, I think at least sanding will provide a better  surface for the stain to penetrate and 'grip'. Is there a reason that it does not need sanded or power washed?It looks pretty dirty/moldy/mossy to me. What should it look like after stripping?

Then again, I've never stripped a deck so I have no idea how powerful the stripping agent is. I'm not trying to be difficult, I'm just trying to understand more of the why's and how's. If I don't have to spend time sanding and still achieve the same outcome then great. However, I'm willing to put in more effort for a better outcome. But if it all boils down to preference, then that's fine, too.

Is pressure treated pine considered a 'hard wood'? or can I use any stain on it?

Glad I didn't order a softwood stain before knowing. 

Does it being PT make any difference in sanding it? Should I pressure wash it?

I bought my house last year and have no idea what type of wood the deck is. I’ve been researching on here and figured l’d post.  I want to buy the right stain for it. I dont know if its hardwood, PT, previously stained, etc.

My plan is this:

ID wood. Buy stain accordingly.

Strip previous stain. I believe it was stained but l know NOTHING about decks so it may not have been. I figured it cant hurt to strip what isn’t there anyway since it will clean it, too.

After stripping, sand it down w a orbital sander and apply brightener.

Apply Armstrong Clark semi transparent stain. Two coats. Haven’t decided color since l dont know the wood type.

l’ve attached some photos(l hope!)

Any and all help would be appreciated!

420,421,422,419,423