Guide To Planted Aquarium Aquascaping – Iwagumi

Introducing the Guide To Planted Aquarium Aquascaping series where we’ll be exploring various styles of aquascaping such as Nature, Dutch, Iwagumi, and Biotopes. We’ll break them down in multiple blog posts with each explaining a certain style in depth along with how to recreate one for yourself to enjoy.

More often than not, we produce rock-only Quick Scapes. They seem easy, but they’re really not! We do these often because rock scapes are usually most pleasing to the eye if arranged, planted and maintained correctly. When it comes to Iwagumi rock scape planted tanks, there’s more to it than what meets the eye. Many aquarium hobbyists, at one point or another, have wanted to try this deceivingly simple aquascape style; however, achieving a favorable end result can be daunting. Before we take a deeper dive into this interesting aquascape style, let’s briefly go over it.

What is Iwagumi?
The art of Iwagumi is closely tied to and inspired by ancient Japanese and Chinese garden rock arrangements that replicate natural landmarks such as mountains, lakes, hills, and plains. Nature simply has a strong influence on Iwagumi aquascapes. The meticulous placement of rocks provides the groundwork for recreating natural layouts that convey a feeling of bold aesthetic while remaining serene.

What types of rocks are appropriate for Iwagumi?
The rocks we would suggest for an Iwagumi aquascape are Seiryu Stone, Ryuoh Stone (our favorite), Ohko Dragon Stone, Elephant Skin Stone, Lava Rock, and other inert, aquarium appropriate rocks. All rocks will vary in size, texture, characteristic, and coloration by nature even if they are the same type of stone. This is due to varying weather conditions and other natural elements that are contingent upon the region where the stone is found. Because aquascaping rocks of the same overall type can be found in many different regions, we recommend purchasing your choice of stone from a single source to ensure overall visual uniformity. To give a quick example, Ryuoh Stone found in one part of China may have slightly different characteristics when compared to another region of China even though they are essentially the same stone. A key component to Iwagumi layouts is making sure the aquascape rocks being used possess the same attributes to ensure the overall result flows naturally and is visually pleasing. This includes, but is not limited to, textures and coloration.

Once you have chosen the stones you will be using in your Iwagumi layout, we recommend spraying them down with a power garden hose and scrubbing them down with a hard bristle brush to expose the true coloration and texture of each rock. If you’re happy with the results, its time go to town.

How many rocks do I need?
In most cases, odd numbers work best in an Iwagumi planted aquarium. Generally speaking, using an odd number of rocks allows the aquascaper to create a less symmetrical layout which usually produces a much more natural feel in the Iwagumi aquascape such as the Quick Scape example below.

What sized rocks do I need?
Without getting too technical, having several small, a few medium, and one large rock should do it. The smaller rocks should be 1/3 in size compared to the large stone, while the medium rocks should be 2/3 in size compared to the large stone.

Now that I have the rocks, how do I place them correctly?
Once you have your rocks ready for the hardscape, they should be sorted in the following manner:

• Small rocks = Accents
• Medium rocks = Supporting
• Large rock = Main

The largest rock should be set in place first as it will be the main focal point and the rest should be built around it to compliment. Minor adjustments can be made while the hardscape layout evolves during the hardscaping process. As a general rule of thumb, the largest rock should be placed off-centered either closer to the left or right third quadrant of the tank.

The main reason for this is the equivalent of using an even number of rocks in an Iwagumi planted aquarium. If the main stone is placed in the center, the overall look of the tank would look too symmetrical and unnatural. If the large rock is not able to stand on its own, a medium rock can be used to support it at the desired angle and tilt. Next, the supporting medium rocks are placed in the surrounding areas to create natural depth within the tank. Using too many medium rocks can also throw the natural balance off causing the aquascape to look “crowded”. Remember to leave room for the smaller accent rocks. Lastly, once the medium rocks are set in place, the small rocks can be added as finishing touches to the Iwagumi layout.

One thing to note about the small rocks is that they tend to get overwhelmed and covered quickly by aquatic plant growth as the planted tank matures. Due to this, aquatic plant choice(s) and regular precise plant trimming are extremely important in order to maintain a longterm Iwagumi aquascape.

Another important memo to keep in mind is that moving rocks too frequently has the potential to slowly crush new planted aquarium substrate. This will dirty and cloud a newly filled planted aquarium. To avoid this, we recommend tinkering with the Iwagumi layout in a used aquarium tank or using old substrate for practice. Once your rocks are arranged to your liking, then you can replace the substrate with what you will be using permanently. After planting your choice of aquatic plants, it’s time to either fill your tank or proceed with the Dry Start Method.

What aquatic plants are suitable for Iwagumi aquascapes?
Traditional Iwagumi planted tanks utilize no more than 1 – 3 different species of aquatic foreground plants. This is a very loose general “rule” that helps to simplify this style of aquascape and is also another reason why Iwagumi planted tanks are usually mistaken to be easy. There are many Iwagumi planted aquariums that utilize multiple species of aquatic plants. Some include the addition of various stem plants or a mixture of different aquatic foreground plants. Some of the most popular aquatic plants featured in Iwagumi aquascapes are: Eleocharis Parvulus Mini AKA Hairgrass, Micranthemum ‘Monte Carlo’, Hemianthus Callitrichoides AKA Dwarf Baby Tears, Glossostigma Elantinoides, or Lilaeopsis Novaezelandiae AKA Micro Sword. Iwagumi aquatic plant choices are ultimately up to the aquascaper. We personally stick to 1 – 3 aquatic plant choices due to our own preferences and amount of time we’re able to dedicate to aquarium maintenance.

Regardless of your plant choice, it is always important to use a high-quality and reputable planted aquarium substrate such as Ultum Nature Systems x Marfied Controsoil or Tropica Aquarium Soil because aquatic foreground plants rely heavily on its substrate for nutrients, unlike stem plants.

Is there a required tank dimension for an Iwagumi layout?
There is no required tank dimensions for creating an Iwagumi and Iwagumi layouts can ultimately be created in virtually any tank size so long as the aquascaper has the desire to do so. Although, in our experience, standard sized and long tanks are much more generous in layout space available for rock selection and creation of depth. It’s more difficult to find a batch of uniform rocks that will fit a specific aquarium tank size than to find uniform rocks followed by an appropriate tank to house them. Standard sized tanks and long aquariums also allow for more open horizontal water flow and swimming space for tank inhabitants.

What tank inhabitants do you suggest?
Tropical schooling fish are our general go-to for Iwagumi planted aquariums. As mentioned above, Iwagumi style is inspired by natural landmarks such as mountains, lakes, hills, and plains. With that in mind, the school of fish is portrayed as a flock of birds. Smaller Tetras such as Neons, Ember or Cardinals and Rasboras such as Harlequin, Espei or Kubotai, are some of the best choices for Iwagumi layouts for their size and schooling behavior. In our experience, Rasboras generally school tighter than Tetras, although, Rummy Nose Tetras have been known to be tight schoolers in open water as well.

Other notable aquarium inhabitants are Otocinclus Algae Eaters and Amano Shrimp. Iwagumi aquascapes usually feature smaller foreground aquatic plants. Smaller foreground plants are also generally harder to clean. The inclusion of  Otocinclus Algae Eaters and Amano Shrimp aides tremendously in helping to keep algae at bay. These little critters also feature an unobtrusive size, color, and temperament, making them a near perfect clean-up crew with little to no distraction from the Iwagumi layout.

It’s important to note that patience is crucial when creating an Iwagumi layout. After your aquascape is fully matured and stocked with inhabitants, it’s time to sit back, relax and enjoy your slice of nature!

If you’re still having trouble with rock choices or feeling overwhelmed, check out our Quick Scapes, Shop The Look or Order Custom Hardscape pages for pre-made aquascapes by our team, inspiration or a custom Iwagumi layout tailor-made for you. Happy scaping!