Best pressure washer for cleaning a deck before staining?

Hey folks, I'm tackling a deck refinishing project this weekend and need some advice. I've got a 20x15 pressure-treated wood deck that's looking pretty grimy with some mildew spots. I want to clean it thoroughly before applying new stain. What PSI and nozzle tip should I use? I've got access to a few washers but don't want to damage the wood. Also, any chemical recommendations? Thanks in advance!

Steve, listen up - you don't want to go over 2000 PSI on wood. I've seen DIYers blast the grain right out of decking with those 3000+ units. Use a 25-degree nozzle, keep the wand moving, and stay 12-18 inches from the surface. For chemicals, simple oxygen bleach solution works better than harsh chlorine stuff. And wear eye protection - I've had deck splinters in my safety glasses that would've been in my eyes.

Ooh deck cleaning! I've got 7 pressure washers in my collection (don't judge lol). For your project, I'd recommend the Sun Joe SPX3000 - it's 2030 PSI max but you can dial it down. The 40° turbo nozzle is perfect for decks - less chance of etching. Pro tip: work WITH the grain, not against it. And definitely pre-treat with a deck cleaner, let it sit 10 mins before washing. Post pics when you're done!

Thanks guys! SafetySteve - good call on the distance, I probably would've gotten too close. Patty - I'll check if my neighbor has that Sun Joe model. One more Q: Should I sand after washing or will the pressure washer prep it enough for stain?

Let it dry 48 hours minimum, then sand any raised grain. Pressure washing opens up the wood fibers - that's normal. Light 80-grit pass, vacuum thoroughly, then stain. And check for loose boards/fasteners while it's wet - easier to spot issues. Don't rush the drying like I did on my first deck... had to redo the whole thing.