Dragon Stone—also called Ohko Stone—is a star material in the planted aquarium world. According to aquascaping experts, it’s prized for its “organic, dragon-scale texture” that instantly adds dramatic depth to underwater landscapes (. Composed of lightweight clay-like sediment, it’s largely inert and won’t significantly affect water chemistry—perfect for delicate setups . With strategic placement and preparation, Dragon Stone becomes the centerpiece of mesmerizing aquascapes, from minimalist Iwagumi to lush jungle-themed tanks.
What is Dragon Stone & Why it’s a Favorite
Dragon Stone is a type of volcanic-derived mudstone known for:
- Striking texture: layered, porous “scaly” surfaces that echo mountain landscapes.
- Natural earthy tones: ranging from gray and brown to greenish hues.
- Fish‑safe and inert: won’t shift pH or KH in freshwater aquariums once properly rinsed
- Lightweight: easier to lift and position compared to denser rocks like Seiryu .
- Porosity invites growth: ideal for anchoring plants, mosses, and beneficial biofilms .
Choosing & Preparing Your Dragon Stones
Choose the Right Sizes
- Mix sizes: combine large statement pieces with medium and small stones—this creates natural hierarchy and depth.
- For small tanks, pick 2–4″ stones; larger tanks can fit 6–12″ centerpieces.
Thorough Cleaning & Soaking
- Dragon Stone often contains dust and mud in its crevices—scrub and rinse it repeatedly under running water .
- Soak the stones for a few days (or up to 10 with warm water or diluted hydrogen peroxide) to avoid cloudiness .
- After soaking, test water hardness (KH/TDS) to ensure no minerals are leaching.
Optional Trimming
- These stones are relatively soft—use a hammer or chisel to shape height or flatten sections for stability .
Designing & Hardscaping
Creating Visual Depth
- Position larger stones forward, tapering to smaller ones—use the “rule of thirds” for dynamic viewlines .
- Rotate stone peaks diagonally to suggest movement and mimic mountain ridges .
Securing Structures
- For tall or layered setups, secure stones using aquarium‑safe epoxy, super glue (cyanoacrylate), or anchor with wooden dowels.
- Clear acrylic rods can help support stones partially above water in paludarium or waterfall features.
Choosing Aquascape Styles
- Iwagumi: Use three to five stones as focal points; maintain symmetry and a natural mountain silhouette.
- Nature-style aquarium: Combine wood, stone, and plants to simulate riverbanks or valleys .
- Jungle layout: Integrate stones amid lush greenery to create cave-like structures and visual depth.
Planting & Styling Ideas
Plants That Thrive on Dragon Stone
- Java Moss, Java Fern, Bucephalandra, Bolbitis heudelotii—these attach directly onto rock surfaces .
- Cryptocoryne, Dwarf Hairgrass, Monte Carlo for carpeting around the base .
Reddit tip: “African Water Fern (Bolbitis heudelotii) will stick nicely to the rock…”
Placement Strategy
- Anchor moss and ferns in crevices using fishing line or threads; let nature reveal hidden layers.
- Build layering: tall plants at rear, mid-height along stone bases, carpets foreground.
Maintenance & Algae Management
- Lightly brush stones during water changes to remove algae.
- Trim fast-growing plants to keep stone surfaces visible and picturesque.
- Lower nutrients/lighting if algae blooms challenge the layout.
Care & Long-Term Maintenance
- Stone is durable but can crumble over time; handle gently.
- Inspect stability monthly—loosened rocks can disturb the scape.
- Clean, reseal, or adjust epoxied areas seasonally to ensure structural safety.
Frequently Asked Questions
What is Dragon Stone used for in aquariums?
Dragon Stone (aka Ohko Stone) is used as a hardscape element to create natural, rugged underwater landscapes without affecting water chemistry
How do I clean Dragon Stone for a fish tank?
Scrub thoroughly under running water with a soft brush, soaking for several days to clear dust and organic debris .
Will Dragon Stone affect my tank’s water chemistry?
No—Dragon Stone is inert and safe for freshwater tanks, especially after proper rinsing and soaking .
What plants can I use with Dragon Stone?
Great options include Java Moss, Java Fern, Bucephalandra, African Water Fern, Cryptocoryne, and carpeting species like Monte Carlo .
How can I secure tall Dragon Stone formations?
Use aquarium-grade epoxy, super glue, or clear acrylic rods; dowels drilled through stone offer extra support .
Is Dragon Stone suitable for all aquarium styles?
It suits Iwagumi, nature-style, or jungle layouts. In biotope/Amazonian tanks, it may appear out of place unless fully covered with plants .
Final Thoughts
Dragon Stone is a versatile, visually commanding hardscape option for aquarium lovers. Its texture and porosity invite growth and play with depth, while its inert nature ensures safety. Thoughtful selection, thorough preparation, careful hardscaping, and plant integration yield outstanding aquascapes—from serene mountain vistas to lush forest valleys. Let your creativity flourish, and enjoy the art of crafting nature underwater.