Dragon Stone

Also sold as Ohko-seki · Dragonstone · Ohko · Dragon stone (Ohko)

Synonyms Dragon rock · Ohko stone · Ohko rock · Oko stone

Dragon Stone is an aquascaping rock sold by the piece, typically around 12 × 12 × 8 cm (4.7 × 4.7 × 3.1 in). In the water it leaves the water chemistry alone, does not tint the water, and sinks straight away.

Dragon Stone

At a glance

MaterialRock
Raises hardnessNo
TanninsNone
In the waterSinks right away
EdgesSharp
PrepRinse
Default size12 × 12 × 8 cm (4.7 × 4.7 × 3.1 in)

Before it goes in

  • Dragon Stone is inert: it will not move KH, GH or pH, so it is safe in a shrimp tank and in soft water.
  • Before it goes in, rinse it.
  • It has sharp edges — worth keeping in mind next to long-finned fish and around fish that sit on the bottom.
  • 7 different pieces of Dragon Stone are modelled, so the one you place looks like one you could actually pick out of the bin.
  • A default piece is 12 × 12 × 8 cm (4.7 × 4.7 × 3.1 in); you can stretch it to whatever you bought.

Does it raise pH and hardness?

No. It is inert, so KH, GH and pH stay where your tap water puts them.

Do I need to prepare it?

Yes: rinse it before it goes in.

Will it tint the water?

No.

Is it shrimp- and fish-safe?

Yes. It does have sharp edges, which is worth a thought around long-finned and bottom-sitting fish.

What it goes with

Often compared with

Dragon StoneKei StoneManten Stone
RaisesNoneNoneNone
TanninsNoneNoneNone
In waterSinksSinksSinks
PrepRinseRinseRinse

More hardscape

Plan a tank with Dragon Stone →

Sources (2) · checked Sep 2026