While the lush green background of planted aquariums and, or the dazzling display put on by fish or shrimp in planted aquaria may be the focal point, a hardscape is an integral part of your aquascape. One of if not the most popular is a stone from Japan, you know it as Dragon Stone or Ohko stone locally. The stone derives its name from the shimmery golden-green light it reflects when hit just right by the light, its a simply stunning display. Dragon Stone is made from mudstone, a relatively light clay in comparison to other commonly used hardscape material. It's extremely porous, which makes for great hiding and refuge areas for small fish and in particular, shrimp, such as Amano. It's also a great anchor for plants.
Let's go over why its so popular, by looking at its stats.
Traditional Name: Ohko Stone
Common Names: Dragon Stone
Habitat: Lakes, ponds & estuaries
Density: (g/cm3): 1.85g – 2.5g
Hardness: 2 – 3
pH Impact: Neutral (No Effect)
Elemental Type: Sedimentary Rock (Clay)
One of the most noticeable stats here is that Dragon Stone is that it has no measurable effect on pH, a huge advantage in trying to maintain the oft finicky water chemistry of planted aquariums. Having an inert composition is what makes this stone challenging to attain at times due to popularity demands. This is especially of good note to those using CO2, which has acid that can dissolve lime on other rock and stone negatively effecting both the pH and hardness of your water.
One of the ways you can prepare your dragon stone for your aquarium or vivarium is by rinsing any potential settled dust with a medium pressure hose and allow to air dry.
Another advantage of Dragon Stone being lightweight and porous is that it is easily stackable and securable. Many aquarists use this to their advantage to give their aquarium unique Amano or bonsai style looks.