I’m relatively new to backpacking and bought an Osprey Atmos 65 pack. I was wondering what liter dry sacks everyone typically used? I’m going to be on trail probably no more than 3 days at a time.
Use a compactor bag as a pack liner and some Freezer Ziplocks for small stuff. If you keep you sleeping bag in the lower compartment you can keep it in its own compactor bag. You just twist the top closed and tuck it in.
You do probably want a dry bag for food especially if you need to hang it against bears and general crtterage. 5L is probably a minimum size for that. A BV450 bear can is about 7L and suggests it is large enough for 4 days.
You may want something a bit better than a diposable Ziplock if you carry expensive electronics.
I would recommend you use simple groceries bags for the first hike or two and get a feel for the amount of items you like to take. Each person is a bit different. Once you figure out exactly what you want with you, that will inform you of the sack sizes. No need to buy one size today and learn you should have gotten a different size. Also, hikers tend to start heavy and move lighter and some event get to the point of a compactor back inside to provide waterproofing and a food sack for hanging so you might be buying something you don't use for long. More reason to test it out first 🙂 Good luck....hike your own hike
I beelieeve your pack domes with a rain cover. That should e sufficient. It is often a good idea to carry a trash compactor bag in your gear - a wonderfully versatile item.
For your initial trips, check the forecast and try for good weather. Hiking in thee rain has its pleasures, but they can wait.