I use a 3 pound folding anchor with my Outback and it works very well.
Make sure you have enough anchor line so the "scope" is at least 3:1.....5:1 is better.
Scope is the depth of the water x the distance back from the anchor......a shallower line angle between the kayak and anchor on the bottom quickly improves the "holding power" of the anchor.
So if you are in 30 feet of water and the wind is not howling or there is not any appreciable swell/chop, 30' x a scope of 3 = 90' of anchor line.......if it's really howling, you could easily need 150' (5 x the depth) of anchor line to make it "stick/hold".....