I am in the process of refacing my deck with the same type of 2"X6" treated lumber that was original. I am using 3" Phillips deck screws from Lowe's. The lumber has knots and I am thinking of using Minwax or Ace wood filler to cover screw holes inperfections and knot holes prior to staining and waterproofing. Both fillers mentioned are good for outdoor use. Thanks for any suggestions you may have.
Pet41

I would use 2 1/2 inh sqare drive screws and drive the screw a bit under the surface of the 2x6 and not worry about a filler that will pop out anyway when the wood dryes.

I would not bother with trying to put wood filler in screw holes, it will not last long. Be sure your screws are rated for exterior use on this type of wood. Some treaeted wood reacts with certain screws so getb thr right stuff. Home Depot and Lowe's also offer a type of deck board attachment that works from the side with no screws or nails showing. A bit more expensive but what a great appreanace. It is a plate with teeth that you drive into the slide of the deck board righ on top of the joist, then you screw through the plate into the joist.

Spend the money and get something without knots, over 20 years it will save you a lot of money