Ohko Dragon Stone Sourcing Singapore: Quality and Pricing
Genuine ohko dragon stone is a clay-based sedimentary rock with characteristic honeycomb pitting, and roughly half of what sells as “dragon stone” in SG is actually tufa or pumice stand-in. Proper ohko dragon stone sourcing singapore research saves you from paying premium prices for an inferior substitute that crumbles within six months of submersion. This guide from Gensou Aquascaping at 5 Everton Park walks through current shop pricing, authenticity checks and the freight logistics that affect cost. Whether you are building a 45 P shrimp scape or a 120 cm showpiece, knowing your supplier matters more than the stone’s label.
What Ohko Actually Is
Ohko, sometimes called Seiryu’s softer cousin, is a Japanese aquascaping term for pitted clay rock quarried originally from Niigata. Today the overwhelming majority sold globally comes from Shandong or Anhui provinces in China, where similar geology yields the same characteristic texture. The stone is soft, carves with a screwdriver, and weighs roughly 1.8 g per cubic centimetre. It is inert in most freshwater conditions, which is why soft-water SG scapers favour it over carbonate-heavy alternatives. Background on Japanese scaping tradition sits in our nature aquarium guide amano piece.
Current Pricing at Local Shops
As of early 2026, C328 Clementi lists ohko at around $9 per kilogram for medium grade, with premium selected pieces at $15 and up. Iwarna stocks curated larger statement stones at $12 to $20 per kilogram. Polyart and Nature Aquarium carry similar grades; Reef Wonderland tends to lean marine but carries freshwater hardscape seasonally. Carousell listings range from $5 for bulk broken pieces to $25 for photographed signature stones.
Identifying the Real Thing
Genuine ohko shows deep, irregular honeycomb pitting that goes into the stone, not just surface texture. Crumble a corner between your thumbnail and a hard surface; real ohko leaves a fine clay dust without loose grains. Pumice substitutes feel lighter and show bubble cavities rather than weathered pits. Tufa shows uniform vesicular texture without the angular relief. When in doubt, ask the shop to cut a piece and inspect the interior.
Size Grading and Project Matching
Shops typically grade ohko as fist, head, or statement. A 60 cm iwagumi needs one statement piece of around 4 kilograms plus three to four head-sized supporting stones. A 45 P shrimp scape wants fist-sized pieces only, roughly 2 kilograms total. Buy 20% more than the calculator suggests because cutting and pose-fitting always wastes stone. For layout theory see aquascape using ohko stone only.
Weight and Transport Logistics
Ohko for a typical 90 cm tank runs 10 to 15 kilograms. GrabExpress and Lalamove can handle the load but quote accordingly; expect $15 to $25 per trip for cross-island delivery. HDB lift access usually fine, but bulk orders over 25 kg warrant two trips or a friend’s help. Serangoon North and Clementi shops both offer delivery for orders above $100, which frequently pays for itself on hardscape-heavy builds.
Quality Red Flags
Reject pieces that sound hollow when tapped, flake under light pressure, or show white efflorescent deposits. Old stock stored in damp warehouses accumulates mould and calcite that wreck aesthetics and can spike parameters. Freshly quarried stone should smell mineral, not musty. Our how to prepare rocks aquarium guide covers the scrubbing protocol you should run regardless of source.
Online Versus Brick-and-Mortar
Shopee and Lazada surface cheaper ohko at $4 to $6 per kilogram, but shipping doubles the price and you cannot see individual pieces before paying. For feature stones that anchor a composition, go in person. For bulk fill behind visible stones, online bulk lots work if you accept the visual compromise. Iwarna and Polyart also list WhatsApp ordering with photos, which is a reasonable middle ground.
Pairing With Substrate and Plants
Ohko’s pale tan colour contrasts beautifully with dark ADA Amazonia or Tropica soil. Pair with rhizome plants like Anubias nana petite and Bucephalandra that attach to its pits naturally. Use wedging rather than glue where possible; the porous surface does not always take cyanoacrylate well. Further pairing logic lives in our dragon stone ohko aquascaping article.
Long-Term Stability
Good ohko lasts the life of the tank. Poor substitutes crumble after 6 to 18 months, releasing sediment that clouds the water and smothers plants. If you notice sand-like accumulation at the base of your stones after a year, you bought pumice or weathered tufa, not ohko. Warranty replacement is rare, so pay the premium once and keep your receipt.
Fitting Ohko Into Singapore Tanks
Ohko’s inert nature suits our soft tap water perfectly; no kH swing to manage, no calcium dump to buffer. In HDB tanks with limited footprint, its voluminous-looking structure gives visual weight without adding actual mass. Pair it with careful substrate slopes as described in advanced aquascape layered substrate depth and you get a scape that punches above its tank size.
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Still Have Questions About Your Tank?
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5 Everton Park #01-34B, Singapore 080005 · Open daily 11am – 8pm
