Aquascape Iwagumi Beginner's Guide

Published on September 10, 2019
Aquascape Iwagumi Beginner's Guide

The Concept behind Iwagumi

A natural-looking stone formation adds up an exotic touch to the simple creation of aquascape iwagumi. Although a modest setting in aquascape is a sight to behold,

The prime aesthetic of this design is how the stones form in balance with some limited plants and a species of fish organizing a school.

It may seem easy, but it's not, for it involves skills, creativity, and experience, thus one of the most challenging styles in the art of aquascaping.

Simplicity is elegance, and this is what aquascape iwagumi wants to portray. The art embraces the theory of purity and adapts the relevance of spirituality.

The Inspiration

Aquascape iwagumi is an aquarium landscape invented by Takashi Amano. He is a well-known pioneer of a naturalistic concept in aquascaping. Being a wildlife photographer, Amano gained the skills in observing the natural environment and the flow of water in relevance with the stone formation from the forces of nature.

iwagumi meaning

Inspired by Japanese nature and its simple yet rich culture, Iwagumi style aquascape is becoming a trendy design in themed aquariums today, which translates to “rock garden.” Anyone can be an artist at the strike of inspiration. This art exhilarates the enthusiasm of hobbyists to experiment. Let the novice get the experience and ponder on his creation.

This Japanese-style rock-dominated planted aquarium portrays how less of décor can appear more in the eyes of the beholder.

The Scope

The iwagumi style is particular with balancing the open space, the rockscape, and the minimal fish and plant in mind. It is the general layout in every iwagumi tank.

I surmise that the fish and plants are not the centers of attention in this design. The rocks formation plays a crucial part in conveying the iwagumi style through how you placed them, just like how they surfaced in the wild.

You notice that in this aquascape, not all large stones are in one group and the smaller rocks in another. There’s always uneven rock formation, and each rock varies in shapes, sizes, and textures from the others.

Rocks form their layers through sediments caused by the forces of nature either on land or in the sea. The heat,  pressure, and chemical reactions form uneven strata on the faces of these sedimentary rocks.

This is what aquascape iwagumi seeks to achieve as conceived by the artist. It mimics the natural formation of rocks, namely, one large rock with stones surrounding it, sometimes with one or two medium-sized rocks.

Make this your focal point in laying out an iwagumi tank to achieve the rugged look by being natural. This minimalist style projects pure tranquility displaying only one species of fish and one type of plant, which is a carpeting plant.

The Structure

iwagumi structure

Peter Kirwan [CC BY-SA 3.0 (]

I reckon that its imperfection contributes to its unique style. The whole setup seems simple but remembers you need elegance in that simplicity, which makes the art structure difficult.

Balancing the placements of the rocks to the dimensions of the tank matters a lot.

The rocks in this style act as the main components of the entire structure. To come up with meaningful stone architecture, know that each stone has a corresponding meaning.

If you keep the tradition, using only three stones is what it takes, but the art of aquascape continues to evolve, giving liberty to the artist’s preference. As long as the number of rocks ends in an odd number, you can add more than three pieces.

Odd numbers signify imperfection, and through using this concept, you achieve the natural effect. It is a rule of thumb in the iwagumi to be conscious with the odd number. Choosing an even number means unnatural or artificial.

What the style wants to convey here is the uneven selection of stones portraying no human intervention. Creating symmetry, balance and choosing an even number of rocks are evident of human involvement and therefore unrealistic.

The Basic Layout


Photo by Dũng Nguyễn Việt

Let’s know the layout in iwagumi style aquascape where each stone has a name and meaning to convey.


The largest rock that you see in the layout is the Oyaishi rock which is the focal point of the entire design. This center of attraction angles with the water flow mimicking a natural river rock.


The Fukuishi is the next most massive rock next to Oyaishi and must be like its gradient, tone, and color. By tradition, its place can either be on the right or left of the most significant stone to serve as a balancing piece.


Stressing the appeal of the bigger stones is the role of the Soeishi, which is the third of the most massive rocks in the iwagumi style.


These stones are the smaller ones in the layout and often give reference to the “sacrificial stones” because the thriving plants will always cover. Although the Suteishi can never play the centerpiece role, its rightful place in the stone architecture balances the aesthetic appeal of aquascape iwagumi.

Setting Up:  The Iwagumi Style

aquascape style

Moritz Holzinger [CC BY-SA 3.0 (]

Rock Selection

We now know how this simple Aquascape iwagumi can create a powerful impression by mounding soil and combining rocks. Therefore, rocks play a crucial role in this arrangement.

The rocks you should choose must match the dimensions of your tank. I prefer it textured than smooth boulders for the two most significant rock components of iwagumi style.

Attractive rock pieces can give a strong visual impact. You can add more stones if you like if you want to widen your layout options.

Remember that rocks will appear smaller in the tank than in real life. Choose the natural-looking stones of different sizes than the fine-edged ones that are machine-cut.

The color of the rocks should add bearing being the focal point; they must complement the colors of your chosen fish and plants.

You can collect your rocks from nature if you know how to clean and cure them before using. If you go to some LFS, they might encourage you to draft your layout there and buy what you need.

I trust the rocks sold from Amazon, so I’d instead buy branded ones and let my fingers shop for me.

Light Intensity

Good lighting shimmers on the rippling water. It accentuates shadows that the rocks create. This shimmering effects can project movements to this simple aquascape iwagumi layouts.

It’s easy to provide direct lighting for smaller tanks because of aquascape iwagumi's format.

You need to ensure that your lighting is enough before choosing a plant. A carpeting plant is a common choice for iwagumi style aquascape, and it needs sufficient light.

Suggested Lighting:

  • LED spotlights
  • Metal halide units or Overtank luminaire
  • Two 24w T5 lamps with reflectors, 6-hour photoperiod, or any of the like

Supplemental Needs

Most carpeting plants require CO2 to grow in full. I would never recommend you starting with a carpeted landscape without the injection of CO2.

The aquascape iwagumi looks simple but deceiving. Many experienced aquarists encounter difficulties growing a lush carpet without the needed fertilization and regulated system of CO2 for aquariums.

Suggested CO2

2kg pressurized system on solenoid, glass/ceramic diffuser, 4KH drop checker


Regular lean dose (1/5-1/7) of EI equivalent will work well for Iwagumis. Small carpeting plants draw lower nutrient compared to stem plants. Dosing leaner prevents the carpet from getting thicker and overcrowding fast. You can spot algae and can get rid of them quick.

The Tank

Longer planted tanks need an excellent viewing perspective for aquascape iwagumi so the length of the tank should be twice or thrice the length of the plant in the background.

We want a sense of openness to accentuate a broader horizon. Aquascaping rocks and substrate should dominate a larger front view space of more than half the tank's size.

The ideal water capacity for this scape is from 12 gallons to 20 gallons. Your Iwagumi rocks must match the tank size.

Suggested Tank Profile

I want to recommend you an example tank size for this aquascape.  My aquascape iwagumi tank measures 60 x 30 x 36 in centimeters or 24 x 12 x 14 in inches, 63-gallon water capacity, OptiWhite glass, rimless, braceless.

Filtration System

Canister filters with glass pipes where there’s enough open water make an effective filtration system. I use an external canister with biological and mechanical media, 1,550 lph/341-gallon glassware.

The water flow must be steady so that it can drive enough CO2 to the plants, more so in the substrate level. This process sweeps off the debris from the carpeting plants to the filter intake.

Cleanliness is vital to iwagumi style aquascape to prevent the pesty algae detracting the beauty of this rock work.


Carpeting plants can thrive well with Aquasoil for it allows to dose the water column more with a lot of ease. You can use cosmetic sand if you need a specific color tone, but that will look unnatural for aquascape iwagumi.

More excellent substrates (<2mm) can allow better root growth for your small carpeting plants. Avoid pea-sized and coarser gravel because the roots may not cling tight to it.

The Plants

hemianthus callitrichoides

Photo by Tropica

Since aquascape iwagumi is reminiscent of a massive rocky landscape, a grassy, ground-covering type of plants is a common choice. For the background, use higher-growing plants like Vallisneria nana or Eleocharis vivipara.

You do not have to limit your style with the classic puristic touch, and you can use stem plants or red-colored plants to achieve a softer impression. Iwagumis can evolve, and you can reinvent it as long as you keep the principle of rock formation.

Common plants for aquascape iwagumi

  • HC or Hemianthus callitrichoides ‘Cuba’
  • Glossostigma elatinoides
  • Eleocharis acicularis or Dwarf hair grass
  • Lilaeopsis brasiliensis
  • Blyxa japonica
  • Echinodorus tenellus
  • Pogostemon helferi
  • Staurogyne sp.
  • Riccia fluitans (tied to rocks, submersed)
  • Rotala sp. (background)
  • Eleocharis vivipari (background)
  • Vallisneria nana (background)
  • Micranthemum Monte Carlo
  • Marsilea crenata

The Fish

crystal red shrimp

photo by Emilia Murray

Aquascape iwagumi follows a certain rule not to select a plethora of mixed fish.

As this style connotes purity, several schooling fish belonging to the same species will work great for iwagumi. It depicts the pure tranquility related to the value of water.

Some tiny delicate fish will complement this style well. Fish must swim free in open waters. If you house some large fish,  the rock arrangement may appear small to iwagumi style you wish to express.

Fish and invertebrates for aquascape iwagumi

  • Caridina multidentata
  • Trigonostigma espei
  • Crystal red shrimp

The Challenges of Maintenance

Don’t think when the design is minimal; the maintenance is easy. Remember that there are only one species of plant in aquascape iwagumi. You need to take care of it to thrive and maintain its rich green coloration. Otherwise, your display will look dull.

Plants in Iwagumi are root feeders and to sustain them requires a rich substrate and an effective filtration system. You need to keep the water parameters in good condition and to supplement the plants with additional nutrients to flourish.

Styles like Iwagumi are prone to algae, and you do not welcome this as there’s no bottom feeders or algae eaters housed in your tank to eat this. It makes maintenance arduous for you need equipment to take care of the job.

I presumed every enthusiast in this hobby knows these beforehand. Specific guidelines are at hand when you want a themed aquarium like Aquascape iwagumi

Follow these steps:

  1. Replace half of the water each day for 14 days, twice every week after that.
  2. The moment you establish your carpeting plant,  pruning every week will make them dense and tight.
  3. Fertilize the plants daily.
  4. Clean the filter each month.
  5. Clean the tank glass every week.


Aquascape iwagumi is a rock architecture that implies purity of design. The main criterion is the use of only one stone in different sizes and arranging them through the principle of this Japanese-inspired rock formation.

Since it promotes minimalism, no driftwood or other decorations comprised the layout but solely stones as the focal point, of which number ending in an odd number (3, 5 or 7).

The basic design of Tanshoku Tanei or Aquascape iwagumi translates to just one fish type and one plant species. It is the purest and most straightforward approach to Japanese aquarium landscaping.

There are some iwagumi styles with more fish and plants being colorful and playful, but the purity diminishes in value. An aquarist should maintain the discipline to make his creation descriptive and natural.

The Aquascape iwagumi is a hard-earned but rewarding experience. It embodies the Japanese principles of spirituality, simplicity, and tranquility.

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