It has been 25+ years since Hi Silk 21 Koi food was developed in Japan.

Ever since, people across the world are going crazy over this food because no other food can make their Koi grow as big and fast. Learn more how this food enhances koi skin, makes them grow faster, and overall improves their health. If you’re looking for the best koi food for growth and health, Hi Silk 21 is a top choice.

For those specifically aiming for high-protein koi food for white skin, Hi Silk 21 delivers excellent results. You might also want to compare Hi Silk 21 vs Hi Silk Sweet Potato to see which one fits your Koi’s needs better. Additionally, the silkworm-based koi food benefits are remarkable, offering a natural protein boost that supports both growth and vibrant skin quality.

Curious about how to make koi grow faster and bigger? Start with the right food, and Hi Silk products can make a noticeable difference.

Read our full Koi food guide for ultimate color and growth to learn about all koi foods we recommend. This article is specific to the Hi Silk Koi food products, which we think is incredible!

Video About Hi Silk Koi Food

Hi Silk 21

Why do we love Hi Silk 21? It’s because this food will make Koi grow fast, big and healthy. In addition, silk powder in the food will enhance the Koi’s skin’s white ground to become whiter.

Silkworm pupae

Did you know Koi breeders in Japan used to feed silk worm pupae before these pellet foods were invented? They are natural food and also readily available because at the time, silk industry was big in Japan. The silk worm pupae were by-products of silk manufacturing. Also, from the breeder’s experience, they knew silkworm pupae makes Koi faster, bigger and fatter than anything else.

Why are silkworms so good for growth? Silkworm Pupae Koi Food Benefits

The secret lies in the protein. Protein, once ingested, dissolves into amino acid. Then, the absorbed amino acid will be constructed back to the protein and flesh of the body. The amino acid structure of silkworm pupae is very close to that of Koi. So the conversion rate of the food into nutrients is very high. This is why silkworm pupae are known as the best growth food for Koi.

Disadvantage of silkworm pupae

The biggest concern is the silkworm pupae’s freshness.

Technically, it is a dead caterpillar; so it sounds funny to talk about the freshness. Due to a unique technique, a silkworm pupae can maintain its original form even after 10 years. So amateurs like us cannot tell if the silkworm is 1 day old or 10 years old.  Obviously, if we feed Koi 10-year old silkworms, that will cause some internal problems and make Koi sick. I know there are other silkworm products on the market, but I suggest you be careful and not use them unless you know for sure how fresh they are for the sake of your Koi’s health.

Benefits of Hi Silk Food

Before Hi Silk was created, everybody in Japan wanted to feed their Koi with silkworm pupae products; but at the same time, they were scared to because they did not want to sicken their Koi.

Then about 25 years ago—Mr. Kawaguchi of Kawaguchi Shoten Co., Ltd (pictured above far left) and Mr. Mamoru Kodama, author of Kokugyo books and founder of Kodama Koi Farm (pictured above second to the left)—developed Hi Silk 21.  

Mr. Kawaguchi, a leading supplier of silk and silkworm, provided quality fresh silkworm pupae. Mr. Kodama, a koi expert, designed the food with the silkworm pupae creating amazing Koi growth results.

How does silk powder benefit koi health?

The Hi Silk Food they developed has the same features as silkworm pupae—making your Koi grow fast, big and healthy. We do not have to worry about feeding OLD silkworm any longer. Plus in pellet forms, the quality became much more stable.

Bowl of silk powder

Another surprising ingredient they added was silk powder (powdered silkworm cocoons). Silk powder helps your Koi get snow white skin. Fibroin, an amino acid in silk, is a very good Japanese koi food for liver health. Improving and maintaining the health of liver means snow white Koi skin.

I also personally like the smell. When you open the bag, you can smell the silkworm. The smell also attracts Koi and stimulates their appetites.

Can I combine Hi Silk with other food?

If you are looking for food to make your Koi grow fast, big, and white, this is definitely the one to consider. There are a few suggestions about feeding with this food. Due to high protein, please feed this food only when the water temperature is above 68 °F.

Also, please feed alongside color-enhancing food like Kodama Koi Food Color-Up. Because Koi will grow fast, it is important to combine it with color-enhancing ingredients to maintain or even improve the coloration.

Hi Silk Sweet Potato

Hi Silk Sweet Potato is another product line of Hi Silk series. Just like silkworm pupae, sweet potato is known as a favorite food for Koi and is very sweet. Basically, I think Koi loves the sweet food like we do. Hi Silk Sweet Potato is designed for all seasons, especially low water temperature. 

You can feed your Koi this food all year around. Or if they do not seem to be eating much, feed them this to boost their appetites.

Hi Silk 21 Color

Buy this feed for Hi Silk Growth + Color Enhancement

Hi Silk 21 Color now comes with color enhancement. A combination of astaxanthin, spirulina, and krill enhances koi’s skin color beautifully.

Great for warm weather to grow koi big and enhance their colors. Your Koi are going to enjoy this yummy food

Order Hi Silk Koi food from Japan

We are not kidding when we say that Hi Silk Koi Food will make your Koi beautiful. After years of testing out different products at our koi farm, we are very confident that this is one of your best options. When combined with our color enhancing koi food you achieve maximum benefit.

See all our recommended koi food for your pond. 

Looking to buy new koi fish? We are always listing koi fish for sale on our main website. Check it out!