When I contact the company customer support, they told me is because the way I sharpen my knives are not correct, I put too much pressure on it, so I asked them if that's true, since I am using the same method to sharpen my knives, why it won't happened to the other side (#8000) and the other stone (400/1000)? They don't even give me any answer to that question at all.

Medium Grit Stones: The number range here is from 1000 to 3000, with the latter being the basic, go-to sharpening stone. If your knives have lost their edge and need a good sharpen, then this is the grit you should start with. Don’t use it too often or the knife wears down rapidly. If you like to sharpen regularly, then the 2000 and 3000 grit are the ideal choice as they are less coarse, but please remember they are designed for sharpening and not maintaining the edge.
HIGH-QUALITY DOUBLE-SIDED KNIFE SHARPENING STONE: Coarse side 1000 grit leaves metal edge with frosted appearance. Edge sharpness equivalent to majority of factory edges on knives, tools; Fine side 4000 grit is ideal for finishing and polishing the edge, make edge very sharp, and edge reflects light well. Perfect for light touch-ups to an already sharp.
I give Sharp Pebble a top rating for two reasons. First, the company emailed a user guide for me to review and learn how to best use its product while it was being shipped to me. Wonderfully proactive. Second, the sharpening stone did a terrific job restoring the edge on my kitchen knives that had been woefully neglected. Ever rent a house and every knife in the kitchen has the edge of a butter knife? I was almost there. Now, the knives are cutting beautifully. I have only one suggestion for Sharp Pebble. While the stone includes a useful angle guide that can be attached to a blade and the guide gives clear steps on prepping the stone and how to hold the blade when sharpening, it does not illustrate the manner in which the blade needs to be moved across the stone. I had to go to Youtube to get some tips on the exact method. I have historically been very bad at putting an edge on a blade due to ignorance primarily. But with the help of the video and a good stone, I did an effective job. The base does a great job of holding the stone in place and is attractive in the kitchen.
One of the combinations of stones that I was introduced to several years ago is a unique one, it is a 500, 2,000 and 16,000 grit combination. I was apprehensive when I first tried this, that was thousands of knives ago, it works, it is fantastic combination. It is unique because the traditional way of thinking is that we should be doubling the grit sizes as we sharpen, for example, a 500 grit stone should be followed by a 1,000 grit, then 2,000 grit. This line of thought is meant to be flexible, it is a general rule only, I have broken it countless times.

✅ PREMIUM QUALITY : Our products have been inspected by a reputable third party inspection company. Each product has been checked,put under a durability and functionality test before shipped to you. NO COMPROMISE on quality! This simple-yet-unparalled award winning tool is used by everyone from stay at home moms to various professionals. Don’t forget to buy this as a PERFECT GIFT for your family & friends.
We recommend that customers invest in Kamikoto’s Toishi Sharpening Whetstone to keep handcrafted knives sharp and ready to cut. The Toishi Sharpening Whetstone sits on a beautiful wooden bamboo stand and features two sides – one with a coarse grit to grind away any roughness, and the other with a fine grit that sharpens and polishes the edge. The finer the grit, the finer the edge on your knife. The sturdy wooden stand holds the whetstone safely in place so you can concentrate on gaining the sharpest edge possible.
Visually, a very sharp knife has an edge that is too small to see with the eye; it may even be hard or impossible to focus in a microscope. The shape near the edge can be highlighted by rotating the knife and watching changes in reflection. Nicks and rolled edges can also be seen, as the rolled edge provides a reflective surface, while a properly straightened edge will be invisible when viewed head-on.
This was the first Whetstone that I've ever purchased. After reviewing several 'how-to' videos, I jumped right in to use it. I found the process nearly meditative and the BearMoo stone extremely effective! The first knife I sharpened was very dull with small, jagged edges. The 1000 grit side effectively removed the jagged indentations and created a nice cutting edge. The 4000 grit side made the knife razor sharp. The process took nearly 40-minutes.
This is an important but often confusing aspect of the sharpening process. When you sharpen knives, especially on coarser stones, you'll notice a burr form on the opposite side of the edge. It can be difficult to see, but easy to feel. Carefully feel for the burr by running your finger from the spine of the knife to the edge. The burr will jump from side to side as you sharpen each edge, and once you've felt the burr move to both sides, you can move to the next finer stone. Once you get to the finest grit, the burr will become smaller and smaller!

Understanding Grit: You’ll see a bunch of numbers being thrown around when discussing the grit of a sharpening stone. The number refers to the size of the grit. The larger the number, the finer the grit. A good beginner stone would be a two-sided stone with #400 and #1000 grit. The #400 grit is the courser stone for working out the nicks and imperfections, the #1000 grit is for refining.
Water stones are noted for cutting very fast, but at a cost. The stone itself wears fairly fast and needs to be straightened with a straightening stone now and then, This holds for both natural and man-made water stones, whether Japanese or American, and is by design. American stones tend to stay flat longer but still cut as well as the Japanese.   Photo © Norton Store

When I contact the company customer support, they told me is because the way I sharpen my knives are not correct, I put too much pressure on it, so I asked them if that's true, since I am using the same method to sharpen my knives, why it won't happened to the other side (#8000) and the other stone (400/1000)? They don't even give me any answer to that question at all.
Chefs will do this every day, and there's no reason you shouldn't too. Before cooking, or after you've done the washing up, honing your knife will help keep it in good condition. "When you're using a honing steel, you're not actually removing any metal at all, just re-straightening that edge, to get it back in line," says Authbert. Remember that you'll still need to sharpen it every two or three months. 
Grit choices should fall in line with the steel used to make the knives you plan to sharpen. If your knives are all European, relatively soft steel knives, then you could finish off your knives at the 1,000 – 2,000 grit level. There is a lengthy explanation regarding this topic but suffice it to say that at 2,000 grit, these knives can be made extremely sharp.
The dual-sided whetstone is made from durable silicon carbide and has 400 grit on one side to sharpen the dullest blades and 1000 grit on the other side to create a nice smooth finish once the blade has been sharpened. The stone also forms a nice slurry that helps polish the blade for a superb shine. The stone is meant to be used with water, not oil and for best results, simply soak stone for 5-10 minutes before use, and lubricate with additional water as needed when sharpening.
The dual-sided whetstone is made from durable silicon carbide and has 400 grit on one side to sharpen the dullest blades and 1000 grit on the other side to create a nice smooth finish once the blade has been sharpened. The stone also forms a nice slurry that helps polish the blade for a superb shine. The stone is meant to be used with water, not oil and for best results, simply soak stone for 5-10 minutes before use, and lubricate with additional water as needed when sharpening.
Whetstones may be natural or artificial stones. Artificial stones usually come in the form of a bonded abrasive composed of a ceramic such as silicon carbide (carborundum) or of aluminium oxide (corundum). Bonded abrasives provide a faster cutting action than natural stones. They are commonly available as a double-sided block with a coarse grit on one side and a fine grit on the other enabling one stone to satisfy the basic requirements of sharpening. Some shapes are designed for specific purposes such as sharpening scythes, drills or serrations.[9]
When attempting to choose a whetstone for sharpening your favorite knife, the number of choices can be mind boggling. In fact, sharpening stones are divided into four distinct categories consisting of natural whetstones and manufactured whetstones which, in turn, are divided into two other categories consisting of oil stones and water stones. Then, there are numerous different varieties of natural whetstones consisting of several different materials that are quarried from different places around the world as well as several different types of man-made whetstones!
Japanese whetstones (also called water stones) – both natural and synthetic – are known for their quick-working qualities, not only for Japanese blades, but also for their Western equivalents. The small particles that do the cutting are loosely bound together in the stone, and so during sharpening with the whetstone, the surface particles are quickly washed out, allowing new, sharp, particles to start working on the blade. These whetstones must be lubricated only with water! Never use oil or other lubricants!
It’s a decent stone, especially at this price point. I like generally like King stones. Works fast and wears fairly well. The slurry isn’t as lush and thick as I’m accustomed to but no biggie, and the upside is that I can see my work and am less likely to scratch my blade surface. It’s still aggressive and a little less slurry and pressure seems to make a finer edge on this 1k. I’m no expert but it could be that technique is just improving. Makes a nice bevel. Also, it flattens quickly and isn’t too soft. The unfortunate thing is that it is glued to a cheap hard plastic base and you can’t access both sides of stone. Nonsensical design, but would be tolerable if the base itself were slip resistant. It’s annoying when working on larger and/or heavy blades, thus the lower rating. I had no problems when honing a straight razor or pocket knife. Again, I do like the stone, and it’s inexpensive.
Historically, there are three broad grades of Japanese sharpening stones: the ara-to, or "rough stone", the naka-to or "middle/medium stone" and the shiage-to or "finishing stone". There is a fourth type of stone, the nagura, which is not used directly. Rather, it is used to form a cutting slurry on the shiage-to, which is often too hard to create the necessary slurry. Converting these names to absolute grit size is difficult as the classes are broad and natural stones have no inherent "grit number". As an indication, ara-to is probably (using a non-Japanese system of grading grit size) 500–1000 grit. The naka-to is probably 3000–5000 grit and the shiage-to is likely 7000–10000 grit. Current synthetic grit values range from extremely coarse, such as 120 grit, through extremely fine, such as 30,000 grit (less than half a micrometer abrasive particle size).[citation needed]
High Grit Stones: These are also known as finishing stones with the number range going up to 8000, and give you a super refined edge.  They work great with Western knives as they cutting edge resembles a “U” as opposed to a “V”. If you are using your knife to cut meat, then you can happily stop at 4000 or 6000 grit. If you are only using it for vegetables or fruit go all the way to the 8000.

I was delighted to discover, on opening my recently purchased Kanpeki knife set, single-edged blades. I had never used single-edged blades in the kitchen. I was pleasantly surprised to find each knife was so versatile. Able to do the most delicate cutting, to the workhorse of basic slicing and dicing. I am pleased to say, I will be purchasing the remaining knives and whetstone.
The Juuma sharpening and honing stones offer a simplified working principle while at the same time ensuring the highest possible quality in the offered grits. Juuma Cobalt Blue stones are made of an aluminium oxide and a bonding agent. Adding cobalt serves to slow stone abrasion and increase the speed of sharpening. The speed bonus is especially marked when stoning blue steel (blue paper steel that is often used for Japanese planes and chisels). The cobalt gives the stones their blue colour. Juuma is our proprietary brand. Juuma sharpening stones are produced by a renowned Japanese whetstone manufacturer.
While it may still feel like there is a lot to choose from, you don’t need a lot of of stones, you just a several good varieties to choose from. To summarize I will indicate below what my favourite stones are in each grit. Yes you can mix up the brands when sharpening but my recommendation is to buy a combination of 2-3 stones of the same brand and go from there.
Push the point you want to sharpen with your fingers. While keeping the angle and pushing the point with your fingers, stroke the blade until it reaches the other edge of the whetstone, then pull the blade back until it reaches the edge of the whetstone. This back and forth is counted as one stroke. Repeat it for about five strokes until you can see or feel some small burrs (edge curvatures) Then move the position of your fingers to where you have not sharpened yet, and repeat this five strokes of sharpening processed from the tip to the base of the blade.

The Whetstone comes in a small paper box with instructions. I checked the surface of the stone for flatness and it's about as flat as you can get so a check there. The stone seemed to be overstating the grit but after trying it out and giving it a few runs, the shaved material will actually fill in the gaps and give a good grit on which to sharpen knives on. The rubber feet are nice to have but I place a small mat or board under the stone to keep all the shavings from spilling.

With its premium series Select II, the whetstone manufacturer Sigma Power Corporation from Tokyo addresses users of high-alloy steels such as HSS. These stones, too, are obviously intended to engender a grinding experience similar to that of natural stones. The special production process is expensive, but the Sigma Select II probably has no equal when it comes to demolishing steel.
I bought this wonderful knife on faith. I was told in March when it would ship. I received emails alerting me that my knife would be arriving as promised. It came early, thanks! Tthe quality and feel of the knife exceeded my wildest dreams. I lived in Tsubami ahi where knives are hand forged. This has a place amongst the best. I have it on display for now as I view it as a supreme work of art.
A common myth is that sharpening steels actually sharpen knives, and can replace stones or other sharpening devices. Steels actually hone a knife and help keep its edge if used regularly. A steel should be used before and after each knife use for proper maintenance. Easily enough, it's used the same way you use a sharpening stone. To find the proper angle, hold the knife horizontally with the edge touching the steel. Move the spine upward to create a 45-degree angle, and then half that again for your optimal sharpening angle.

I like the fact that there are two different grits (can be seen as two colors). the black rubber feet stick to the kitchen granite top like glue. The 1000 does a pretty good job of getting a knife roughly there and the 4000 puts on a fine polish for razor a sharp edge. I would go the extra step of stropping the knife after the grinding operation for an extra sharp edge.
Natural Japanese waterstones are still available, though nearly all quarries are closed. However, there still exists a large quantity of mined stone. Quarries containing the finest stones have all but been exhausted. If one were to be found, it would cost a fortune. Even so, similar, less than perfect stones that are currently produced can still fetch well in excess of €400!
So, as you can see, there are numerous different types and grades of whetstones on the market today and each has its advantages and disadvantages. Therefore, the right practice to choose the right sharpening stone for you is to choose a whetstone material based upon how fast you need to remove metal and how fine an edge you need. For instance, although they are often the most expensive type of whetstone, diamond hones generally cut the fastest even in their finer grits followed by Crystolon Stones and then India Stones which are then generally followed by Japanese Water Stones and then by Novaculite, Belgian Blue, and Coticule whetstones in terms of how fast they remove metal. However, it should also be noted that the rougher an edge is, the less sharp it is while, the more polished an edge is, the sharper it is and thus, rough edges are fine for some tools while other tools require a much finer edge and, hunting knives require the finest edge of all. Therefore, the trick to choosing the proper whetstone for any given sharpening purpose is to purchase multiple stones with varying grits to accomplish each given task from cutting an initial bevel or defining a damaged edge to refining an existing edge to polishing it. We hope this article helped you. Feel free to leave a comment below if you have questions.

The video above, from the How To You YouTube channel, explains everything you need to sharpen with a whetstone at home, and the best methods for doing so. Obviously, you’ll need a whetstone (as well as a few other things), and you’ll want to work near your sink or a bucket so you have easy access to water. Fill a container with water, then soak the whetstone in it until it stops bubbling. Inspect your blades for any trouble spots, and get to sharpening using the methods and motions described in the video; making sure to check your progress as you go. We’ve talked about sharpening knives with whetstones before, but this guide is a bit more thorough and the old video has since been removed.