Recommended Stone Grit?

[Magnetite]

If I were to pick just 3 stones (or less) for my sharpening needs, what grit should they be?

Or is there a recommended system?

The primary steel being sharpened is CPM S30V, but others too...

I usually touch up my knives after daily use on what I call my finishing stone (grit unknown), but after heavy use without getting to the stone, it seems to need a little more, but the courser stone I have seems too course, and it has been warn into a slight parabola anyway.

 

[Alberta Ed]

I rely on DMT diamond hones for 99% of my sharpening (an ancient black Arkansas bench stone is reserved for my high carbon steel blades). Highly alloyed steels such as S30V, CPM154, VG-10, ATS-34, BG-42, seem to respond best to diamond hones. I have an extra coarse DMT for re-profiling (which is rarely used), coarse (blue), medium (red) and fine (green). Mostly I use the medium and fine hones. I've used DMT hones frequently for well over a decade and have never worn one out.