AquariumAquatic plant

Blyxa Japonica - Instructions for Planting and Propagation (Blyxa Japonica)

Blyxa Japonica is an attractive aquatic plant known for its use in Dutch and Iwagumi-style aquarium decoration. It grows bushy and has a lovely green texture. However, despite its popularity in aquaponics, this plant is not for the beginner aquarist.

Some aquarists say that Japanese grass is easy to care for and grows like a weed. Really? Why do they disregard the fact that MANY people struggle with it?

The truth is the thing Planting Japanese Grass can be very difficult because of it sensitive to temperature, light, CO2 and nutrition .

You are watching: Blyxa Japonica - Instructions for Planting and Propagation (Blyxa Japonica)

If you are considering adding to your tank, then you will surely find this article helpful. This article provides a wealth of information including how to care for your aquarium plants and the types of potential problems you may encounter with .

Fast facts about Blyxa Japonica

Common nameBlyxa Japonica
Some other namesJapanese grass
Science nameBlyxa Japonica
Tank size (minimum)~ 40 liters
DifficultModerate to difficult
The lightMedium to high 
Optimal PH5,5 – 7,0
Optimal gHMedium
Optimal temperature23 – 26°C
SubstrateEssential (rich in nutrients)
Size10-15 cm
Growth formTrunk
Growth rateMedium 
Location in the tankForeground / Midground
FertilizerNecessary, needs
CO2Necessary, needs
spreadVegetative and by seeds

Classification of Japanese Grass (Blyxa Japonica)

The genus Blyxa of the family Hydrocharitaceae was proposed in 1806.

In 1866, this plant was first described as Hydrilla japonica by the Dutch botanist Miquel Friedrich Anton Wilhelm.

It was later known as Blyxa angustipetala, Enhydrias angustipetala, and Blyxa alternifolia until it was introduced in 1889 by German and Russian botanists such as Paul Friedrich August Ascherson, Robert Louis August Maximilian Gürke, and Carl Johann Maximowicz. .

Note: In aquatic hobby, Blyxa Japonica was first introduced in the early 20th century. However, it was not popular until Takashi Amano started using it in his works.

Habitat of Japanese grass

Its native range is tropical and subtropical South and East Asia.  

Today, Japanese grass has been naturalized in India, Nepal, Meghalaya, Bangladesh, Thailand, Japan, China, Malaysia, Indonesia, Vietnam, Korea, New Guinea, Celebes and in the rice fields of the region. northern Italy.

It can be found in a variety of wet habitats from marshes and marshes (especially sorghum bogs) to lakes, puddles, ponds and riparians, canals, creeks and slow-moving irrigation channels.

Japanese grass grows only 20 cm deep in water. Although this plant prefers shallow water, it is still a fully aquatic plant and cannot be grown in a submerged environment. 

Description of Japanese grass (Blyxa Japonica)


Japanese grass is a green, low-growing plant that is suitable for decorating different parts of medium and large tanks.

Note : Although it may look like some trees like Dwarf hairgrass , Dwarf sagittaria , Cryptocoryne , etc., but that's not the case. The problem is that its stem is very short, especially in young trees.  

This plant has a height of 10-15 cm with thick, thin and narrow leaves, about 7-10 cm long and 5 mm wide.

The internodes of the jasmine stem sometimes remain shriveled and the leaves appear to be darkened.

Leaves are stalkless with sheathed base, pale green, lanceolate, serrated, pointed tip. They have a pronounced midrib with very fine longitudinal veins and a spiral arrangement.

Japanese grass is a species of flowering plant. It only forms lovely white flowers if its stalks are above the surface. However, its flowers are also very pretentious. This means that the stamens separate and collect pollen on the stigmas before the flower fully opens.

The difference between Japanese grass (Blyxa Japonica) and grass grass (Blyxa Aubertii)

  • Thatched grass grows larger, darker, and may turn red.
  • Japanese grass is smaller, brighter green but can turn reddish or yellowish.

Tank requirements and water parameters

Tank Size:

Recommended tank size for growing Japanese Grass minimum is ~40 Liters .

While Japanese grass can technically be grown in smaller capacity tanks (nano tanks), I wouldn't recommend it, as it would require stable water parameters and a CO2 injection. But it's very difficult to do in a nano-tank.

Water type, temperature, gH and pH:

Temperature : The temperature where this plant is grown needs to be adjusted appropriately. The ideal temperature range for Japanese grass to grow is 23 – 26°C.

This plant does not like very cold water and easily rots.

PH : Be sure to monitor the pH of the aquarium water. Basically, the pH from 5.5 – 7.0 is appropriate for this species. Japanese grass needs slightly acidic water.

Stiffness : Soft water is required for the best growth of Japanese grass. Recommended to provide hardness levels from 1 - 5 GH.


Japanese grass is a very deep rooted plant. It requires a nutrient rich substrate , preferably iron-rich soil for optimal growth.

The substrate layer must have a minimum depth of about 2.5 - 5 cm. This gives the plant a suitable environment to cling to its fine and fragile roots, and provide the nutrients it needs for its growth.

Sand or gravel should not be used as they do not allow the plant to take root firmly.

The light:

See more: How To Know If My Aquarium Is Stable?

To grow Japanese grass successfully, you must provide moderately high light by using full spectrum bulbs.

Note : This plant tends to be smaller in high light and a little taller in moderate light.

The availability of high intensity light allows Japanese Grass to achieve a reddish color with more compact growth while low light stimulates upward growth (plants become long-legged) regardless of fertilizing purposes. tree from the very beginning.

In addition, you must keep the lights on for up to 10-12 hours a day.

CO2 and growth:

CO2 : Is it possible to grow Japanese Grass without CO2? Technically it is possible. The only problem is that its growth tends to be slower, less bushy, and denser.

CO2 pump is a necessity for Japanese grass. One can use liquid carbon or pressurized CO2 tanks (20-30mg/l) to provide sufficient CO2 for plants.

Also, under high light, your tank should be balanced in terms of CO2 and nutrients. Otherwise, it will be covered with algae shortly.

Therefore, this plant needs a stable CO2 level to stay healthy and grow in density. So you're better off using a pressurized CO2 system.

Fertilization : This is another beginner's trap. Just having a rich foundation is not enough!

The problem is that Japanese grass is also a versatile nutrient-absorbing plant. It absorbs nutrients through its roots (the media) and water from their leaves. 

This plant requires dosing of liquid plant fertilizer (2-3 times a week) and fertilizing origin  (periodic). The macro and micronutrients will help maintain healthy growth and ensure that the crop maintains its best color.

Attention : Japanese grass needs iron (Fe) – 0.1, phosphate (Po4) – 0.4, and nitrate (NO3) – up to 5 mg/l.

Note : If you keep shrimp in a tank with Japanese grass, you should be aware of the fact that the high CO2 and Copper levels (most fertilizers contain copper) are extremely dangerous for the shrimp.

Caring for Blyxa Japonica

Japanese grass is a plant requires a lot of life and hard It is certainly not the easiest plant to grow in an aquarium. This plant will struggle in low-tech tanks due to the strong need for CO2 supplementation.

In general, Japanese grass is considered a difficult plant to live for a long time. In the scientific literature, this plant is classified as an “annual” or a seasonal plant.

Light is another major factor that determines how this plant will turn out. Need to make sure there is enough high light For proper plant growth, low to medium light will cause the plant to grow long legs and that should be avoided at all costs.

Avoid placing plants in shady places during planting, this is to ensure the plants have enough light to help them achieve the desired bushy effect.

Furthermore, make sure use the fertilizer dosage Rich in macronutrients (Nitrogen, Phosphorus and Potassium) and micronutrients (Iron, Manganese, Boron, etc.) to encourage optimal plant growth and development.

During routine cleaning, remember Stir gently on the plant to release debris , food debris and stems separate on the surface, which can then be vacuumed up.

Finally, make sure Perform regular water changes (25-30% weekly) to maintain good water quality and ensure that water parameters are kept within the proper range.

Until it holds firm, Japanese Grass not a fast growing plant .

In general, this plant will not require much maintenance pruning. It is not invasive. However, removing the oldest leaves from the new ones is always a good idea as these leaves tend to die off.

Planting Japanese Grass Blyxa Japonica

Blyxa Japonica Care Instructions - Planting, Growing and Propagation - planting

Japanese grass is suitable for placing in  foreground and  middle ground  of growing tanks due to its small size and bushy appearance.

  • To grow Japanese grass, first remove the bundle and divide it into parts.
  • Next,  antiseptic   or properly isolate the seedlings (if they are not grown in a test tube).
  • When you're done, place the individual stems in the background and maintain a proper spacing of about 5-8 cm apart to avoid overcrowding and minimize shade.
  • Place the stem 2.5 cm deep into the aquarium substrate to avoid difficult rooting.
    Note : Japanese grass is known to have problems when you first grow it in a tank. However, over time, the plant will develop roots that are 10-15 cm long and wide.
  • Avoid placing Japanese Grass near tall trees that can shade them.
  • Avoid placing Japanese grass too close to the glass. Once it begins to grow densely, the glass will restrict its growth form.

Breeding Blyxa Japonica

Japanese grass can be propagated in two ways:

  • By seeds . Its flowers produce viable seeds that are collected and placed in water.
  • Macrobiotics . The new stems will begin to branch off the base of the main tree, which will spread out on its own and the tree will become even denser. In the aquarium, we need to remove the plant and cut it with scissors. If the new plant has no roots, you can let it float until they grow.

Importance : Don't forget to check carefully for rotting seeds or just bad leaves.

Issues related to growing Blyxa Japonica

Wash: Japanese grass is a species of plant with hairs. There are many reasons why this plant can suddenly rot.

  • The water parameters are stable. Sudden changes (especially hardness and pH) can cause it to rot.
  • Low light, dimming and short optical cycle.
  • Insufficient fertilization.
  • Inappropriate substrate.

Rest period (hibernation):  Japanese grass has a resting period where the growth rate almost stops.

Solution: Check the hardness from the beginning. Providing enough nutrients and keeping it at optimal water parameters will shorten this period to a minimum. Just wait until the tree recovers. Eventually, it will start growing again.

Sensitive to nutrients : Japanese grass cannot survive without nutrition for a long time. It dies from lack of nutrients.
Solution: frequent pooping.

Refer: Instructions for Planting, Care, Propagation of Mangrove Trees – Madagascar Lace

Fragile : Japanese grass has fragile leaves. It is easy to damage them during maintenance.

Solution : Just be very careful when handling this plant.

Difficult to grow:  It can be really difficult to grow Japanese grass in a medium because the young stems are easily damaged. In addition, in the beginning, the stem often does not have well-developed roots to attach to the medium, so it can drift away.

Solution : Use tweezers to plant the plant on the substrate. Place some pebbles or rocks around the trunk. Be careful, the rock must not damage the trunk or roots of the plant.

Food for other species : Japanese grass have fins that some periwinkle and fish can taste delicious.

Solution : Do your research carefully on the species you can release into your tank.

Leg growth Length: Stems may turn yellow and elongate.
Solution : Test your lighting.  

Discoloration : Changes in color can be caused by a lack of iron and phosphates which are essential for optimal health and development.

Solution: Therefore, you should dose liquid plant fertilizer in your aquarium water regularly to maintain a good supply of nutrients for your live plants.

New tank : It has been found that Japanese grass does not grow well in new tank setups. It seems that it requires a certain biological balance in the substrate.

Solution : Wait until the tank stabilizes.

Floating : When Japanese grass splits (propagation), some plants break free from the background and float. Basically, over time, it gets too big to stay in one place.

Benefits of Blyxa Japonica

Blyxa Japonica Care Instructions - Growing, Growing and Breeding - iwagumi aquascaping
Filipe Alves Oliveira's Iwagumi Composition

Beauty :  Japanese grass can be a great decorative addition to your tank.

Not too strong : This is a small plant. That way, it won't choke other aquatic plants. In addition, Japanese grass does not grow quickly to become invasive.

Hideout of fish, fry and shrimp : Japanese grass serves as an excellent hiding place and shade for small species.

Place to feed:  Act as a class  biological layer buffet , is the ideal starting food for newly hatched fish and juveniles .

Prevent airbag:  Japanese grass has well-developed roots  will help break down the anaerobic pockets  in the body.
Note : Bags of hydrogen sulfide (H2S, gas that smells like rotten eggs) can be really dangerous for your fish or shrimp.

Blyxa Japonica and compatible tank mates

The fragile, fragile and easy to feed nature of Japanese Grass makes it picky about suitable tank mates. The plant will survive in a tank with the creature without seeing its soft leaves as a snack. Compatible tank mates include: 


It is best to keep plants with small, peaceful community fish such as  Neon tetras , Killifish, Swordtails, White Mountain Minnows, Zebra Danio , Cherry Barb, Sunburst Platy,  Endlers ,  Mollies,  Otocinclus Catfish , Pygmy Cory Catfish , etc


The fact is that Japanese grass likes slightly acidic water. Therefore, you should consider species that prefer the same water parameters, for example, red shrimp , bluedream shrimp , Caridina cf. babaulti, etc. 

Freshwater snails:

Again, aquarium snails should not be kept in low pH tanks for long periods of time. It will negatively affect their shells. However, if your pH is close to 7.0, you can keep almost any species of snail or shrimp you like.


Japanese grass is an impressive and attractive aquatic plant. This species can be used to create various artistic effects in all kinds of aquatic compositions because of its distinctive form and vivid, striking colors.

However, the main problem is that Japanese grass is not easy to maintain and care for. This plant needs soft and acidic water, CO2, a rich substrate, regular fertilization and strong lighting.

It is therefore more suitable for experienced aquarists due to the high demands and special care required for it to grow healthy and maintain its best color in freshwater tanks.

Refer: What is water cycle? Aquarium Cycle Experience

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