UNS · Stone
Ancient Stone
Iwagumi keepers who like the Manten look and want a slightly darker, more angular stone.
4 models
UNS · Stone
UNS Seiryu Base Stone
A 20 lb selection of long, flat, slab-like Seiryu pieces meant for building structure rather than as feature stones. Use them as retaining walls, supports under main stones and wood, or to shape slopes.
Updated
Best for
Sloped or terraced Iwagumi and nature layouts that need hidden structure beneath the show stones.
Worth knowing
Not meant as main stones, and like all Seiryu it pushes up hardness, so it is a poor fit for soft-water shrimp.
What stands out
- About 20 lb (9 kg) per order
- Elongated, flatter Seiryu pieces
- Same grey colour and texture as standard Seiryu
- Good for terraces, retaining walls and substrate transitions
Specs
| Model | Weight |
|---|---|
| 20 lb boxUNSHLSS01-20 | 9.1 kg |
- Brand
- UNS
- Effect on water
- Raises KH, GH and pH (calcareous, like all Seiryu-type stone)
- Colour
- Classic Seiryu grey with white veining
- Texture
- Jagged, grooved
- Origin
- China
- Prep
- Rinse and scrub well before use
Figures from Glass Aqua's product listing. Makers revise products, so check the current figures before buying. Photos supplied by the brand or its distributor.
What seiryu stone does to your water
It contains calcium carbonate, so it dissolves slowly and pushes pH and general hardness up over time. The effect is stronger in soft, low-buffered water. If you are aiming for a soft-water shrimp or blackwater tank, seiryu will fight you; for a harder community it is fine. Test with a drop of acid, it fizzes.
Full Seiryu Stone guideCompare with
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UNS · Stone
Ashen Stone
Minimal or river-style scapes that want bright, soft stone against lush green planting.
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Black Lava Rock
Budget-friendly builds, nano tanks and moss-covered scapes that need plenty of stone volume.
1 model
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Black Lava Rock Cave
Shrimp and nano tanks that need hiding spots, or scapers wanting planted pockets at different heights.
4 models
Frequently asked questions
Quick answers about the UNS Seiryu Base Stone, drawn from its specs.
Does Seiryu Base Stone affect water chemistry?
Raises KH, GH and pH (calcareous, like all Seiryu-type stone).
How do I prepare Seiryu Base Stone before use?
Rinse and scrub well before use
Who is the UNS Seiryu Base Stone best for?
Sloped or terraced Iwagumi and nature layouts that need hidden structure beneath the show stones.
Is there anything to watch out for with the UNS Seiryu Base Stone?
Not meant as main stones, and like all Seiryu it pushes up hardness, so it is a poor fit for soft-water shrimp.
What are the alternatives to the UNS Seiryu Base Stone?
Other hardscape worth comparing: UNS Ancient Stone, UNS Ashen Stone, UNS Black Lava Rock. Add any of them to the compare table to see the specs side by side.