The 220 Grit Medium Aluminum Oxide Water Stone is used for the initial sharpening on all dull knives. The 220 Grit Stone is the one for all purpose sharpening it's not too course to put a good edge on your knife but also not too fine to not cut enough metal. It's just about right. This 220 Grit Stone works the best when used with the Apex Edge Pro Knife Sharpener. To attach to the Apex Edge Pro you will need a blank, which you can get here.
Tip: For that ultra mirror-like shine on your knives try using the 2000 Grit Polish Tapes after the stones.