If you don’t have a problem with the water-lubrication system in your working environment, Waterstones is the most common and affordable models to obtain. They are available in various abrasive grit grade from coarse to extra fine mesh. They generally made by Aluminum Oxide, which provides faster cutting. The downside of the Waterstone, they wear down more quickly as the impact of the old abrasive materials that break the stone itself. It is why Waterstone requires frequent flattening to keep it evenly. It is recommended you have one of diamond stones to help you for regular flattening become easier.
Dull knives aren't just annoying — they can be downright dangerous. Keep yours in top shape with the Sharp Pebble Knife Sharpening Stone. It has a #1000 grit side for dealing with dull edges, and a #6000 side for honing to razor-like sharpness. It sits inside a silicone base, inside a non-slip bamboo base, and comes with an angle guide that slides over the spine, ensuring that even beginners can set a proper edge.

A: When it comes to the best knife sharpeners used in a domestic setting the abrasives used to sharpen the blade should last for quite a few years. When they do eventually wear out many of the best manufacturers will refurbish them for you, typically for a nominal fee. Again, however, unless you are using the sharpener on a daily basis (and there is virtually no reason the average person would do this), the sharpener should last for many years before ever needing service.
"How do I use this daunting metal rod?" I hear you ask. Well, it's not too hard, really. The best way for a beginner is to balance the steel on a surface with the tip secured by a damp tea towel. You want to get that angle right, whether it's around 15 degrees for a Japanese knife or 20 degrees on a German or French blade. Then swipe slowly down, away from you, making sure the whole blade is honed – around five swipes on each side should do. 
To take off the fine scratches and burrs left by coarser stones, and to polish the surface, you can use stones starting at around 2000 grit. There is theoretically no upper limit, but stones above about 10000 grit achieve practically no measurable improvement in the edge. It is also interesting to note that above 8000 grit, there is no Japanese measurement standard. For stones labelled as having a finer grit, you simply have to take the manufacturer's word for it.
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To summarize, Shapton Glass 500, 1,000 and 2,000 is a good combination and if you would like to throw in the 4,000 grit stone in lieu of the 2,000 that is good as well. If your knives are very hard, ZDP 189 for example, this is a fantastic choice. (They are also excellent for tools, chisels etc. and they are the premier choice for many Straight Razor honers).
Now you may wonder, if a finer stone produces a better cutting edge why do I need a coarse stone at all? The answer is that finer stones work much more slowly than coarse ones. The amount of metal a fine stone removes with each pass is much less than what a coarse stone removes. If you have an edge with a good shape to it from a coarse stone, this is not a problem because the fine stone doesn’t have to remove much metal to improve the edge. If the edge is dull, it will take many times longer to reshape it with a fine stone than it would with a coarse one.