Iwagumi

Iwagumi is an aquascaping style built almost entirely around stone placement, with little or no driftwood and typically just one species of plant used as a carpet across the substrate. The name comes from the Japanese word for rock formation, and the style is closely associated with the aquascaper who popularized it as a way to apply traditional garden principles to a small glass box.

A classic iwagumi layout uses an odd number of stones, often three or five, arranged so one dominant stone sets the scale and direction for the smaller stones around it. The simplicity of the layout puts a lot of pressure on stone selection and placement, since there is no dense planting to hide an awkward gap or a stone that does not sit well with the others. Strong, even lighting and consistent CO2 are usually needed to keep the single carpeting species dense and low, since gaps in an iwagumi carpet are much more visible than in a busier layout.

When planning an iwagumi tank, buy stones from the same source and rock type so color and texture match, and lay them out dry before adding substrate to test different arrangements. A common mistake is choosing stones that are too similar in size, which removes the visual hierarchy the style depends on, or planting a carpet species that needs more light or CO2 than the tank can provide.