Im a rookie to knife sharpening and just looking for some tips. I have the sharpmaker and dont know much about the stones. As far as what you want to use for touching your blade up, if a knife is super dull can you use the medium grit stones that come with it or should i buy the diamond stones? And also how many different types of stones are available for the sharpmaker. I see white ones online listed as ultra fine, would those be the same as the ones that come with the sharpmaker? I tried sharpening a persistence that i use for work that is pretty dull the blade has a few little spots that are rolled or chipped off. I went at it for like a half hour trying the 30 and 40 degree angle starting with the medium and finishing with the fine stones and couldnt get the blade profiled back to normal. Does it sound like im doing something wrong or do i need diamond stones for this sharpening? Appreciate the help, like i said im a super rookie to knife sharpening.