Kouroka Lava

Natural Japanese Lava with High Filtering Capacity
Easy Aquascaping

Easy Aquascaping

Being light-weighted, hard and angular,
it is easy to make an aquarium layout,
which is difficult to collapse.

Perfect for Growing Water Plants

Perfect for Growing Water Plants

Plants tend to root on uneven surfaces
to directly absorb the minerals,
providing a natural environment for algae and mosses.
Exellent Water Purification Performance

Exellent Water Purification Performance

Its porosity facilitates the process of
bacteria reproduction and water purification.
It is suitable for aquarium bottom sand.

Amazing Water Absorption Capacity

Amazing Water Absorption Capacity

Its porous property promotes water storage
and absorption by capillary action.
It is suitable for both terrarium and hydroculture plants.

Rich in Natural Minerals

Rich in Natural Minerals

Its mineral-rich nature makes its surface glitter,
and the natural minerals like iron diffuse into the water gradually,
enhancing the growth of plants and shells.

Aquascaping challenge

Aquascaping challenge

Speaking of lava stones, freshwater aquariums might come to your mind.
Why not being innovative by creating marine scaping
with a theme of coral-reef at volcanic islands or submarine volcanoes?

Lighter than ordinary lava rocks by more than half

It is easy for aquascaping, and helps reduce the risk of damaging the aquariums.

Water absorption capacity is twice as much as ordinary lava rocks.

Put Kouroka Lava into 180cc water for testing.
Water passing through the porous surface was absorbed by the lava rock after 30 minutes,
demonstrating that Kouroka Lava
has excellent water absorption capacity through capillary action,
providing a suitable enivronment for filter bacteria.
It is highly recommended for
growing terrarium and hydroculture plants.

Porous in nature with long-lasting durability

High-filtering capacity, long life using

Various sizes from gravel to rocks

It is suitable for aquascaping, bottom sand and filtering materials.

LL size is a limited edition.


Black, red, yellow are available.

You can choose different colours to match with different styles of aquascaping.

Pure black is a limitied edition.

ONLINE SHOP Special Offer on Kouroka Lava

Our Products

Let’s get the rare Kouroka Lava

Large Lava Rock 20~30cm

Spring Inc.

Spring Inc.

We are an innovator of aquarium, manufacturing acrylic tanks
including the world-patented Bird’s Eye Aquarium
in our own factory in Yamanashi, JAPAN.