Top 10 Aquascape Rock Types Roundup: Seiryu to Petrified
Stone defines the bones of every Iwagumi and nature aquascape, and the wrong choice can quietly drive pH and KH up for months. The top 10 aquascape rock types ranked here cover the classic high-end stones, the budget alternatives and the rocks that genuinely leach minerals into your water. This roundup from Gensou Aquascaping at 5 Everton Park ranks each by visual signature, pH impact and sourcing reliability in Singapore. SGD per kilogram pricing reflects current import availability through Iwarna, ANS and ADA-licensed dealers.
1. Seiryu Stone
Japanese blue-grey stone with sharp angular crevices and white quartz veining. The Iwagumi standard. SGD 10-18 per kg. Caveat: seiryu raises KH and pH because it contains calcium carbonate. Acceptable for hardwater tanks; problematic for blackwater or shrimp scapes. Pair with a test kit range to monitor KH drift.
2. Frodo Stone
Pale grey weathered limestone with rounded eroded forms. SGD 12-22 per kg. Also raises pH and KH. Visually softer than seiryu, suits gentler aquascape moods. Imported through ADA-licensed dealers.
3. Dragon Stone (Ohko)
Honeycomb-textured clay stone in pale tan. SGD 8-15 per kg. Inert — no pH impact. Lightweight and porous, plants attach quickly. The forgiving alternative to seiryu for keepers who want texture without water hardness.
4. Manten Stone
Charcoal-grey volcanic stone with rugged angular forms. SGD 10-18 per kg. Inert. The dark counterpoint to dragon stone in mixed hardscape compositions.
5. Lava Rock
Black porous volcanic rock. SGD 3-8 per kg — the budget option. Lightweight, inert, and the porous structure makes it bacterial colonisation gold. Often hidden inside backgrounds as biological filtration mass. Pair with a moss range for instant texture.
6. Petrified Wood
Fossilised mineralised wood with brown wood-like surface and rock density. SGD 15-30 per kg. Inert. Bridges the visual gap between wood and rock — particularly useful in scapes that need hardscape continuity.
7. Slate
Layered grey-black sedimentary rock that splits into thin plates. SGD 5-12 per kg. Inert. Useful for cave construction and shelf formations. Pleco and cichlid breeders use slate for spawning surfaces.
8. Mountain Stone (Yamaya)
Brown-grey weathered stone resembling alpine rock formations. SGD 10-18 per kg. Slight KH impact in some sources — test before committing to a shrimp tank. Suits naturalistic mountain-themed aquascapes.
9. River Cobble
Smooth water-rounded grey stones in graded sizes. SGD 3-8 per kg. Inert. Reliable for stream biotope tanks where polished surfaces match the natural environment.
10. Ryuoh Stone
Sharp angular stone in deep grey with quartz veining, similar to seiryu but coarser. SGD 12-20 per kg. Mild KH impact. The understudy when seiryu supply runs low at local importers.
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5 Everton Park #01-34B, Singapore 080005 · Open daily 11am – 8pm
