Seiryu Rock 20kg Box
Water type
Freshwater
Weight
20 kg
Delivery
Heavy
Aquarium safe / pH effect
Wash well, minimal pH effect
Seiryu Rock 20kg Box
Grey, angular stone for full Iwagumi and mountain-style builds, sold by the 20 kg box. Bioscape Seiryu Rock 20 kg Box is a natural aquascaping stone in light-to-mid grey tones with fine white mineral veining and sharp, angular faces – the stone behind countless Iwagumi and nature-style layouts, supplied as a mixed box large enough for a full aquascape.
Key features
- Classic grey seiryu-style stone – sharp, angular faces with white mineral veining, suited to mountain-ridge and Iwagumi-style hardscapes.
- Calcareous – raises KH, GH and pH gradually – the trade-off for the look; wash thoroughly and bucket-test before committing it to a soft-water scape.
- 20 kg box of mixed pieces – enough for a full-tank Iwagumi build or several smaller layouts.
- Each piece is unique – natural stone, so shape, weight and exact colouring vary piece to piece; the photo is representative, not the exact pieces you'll receive.
Specifications
| Sold as | Material | Colour | Water type |
|---|---|---|---|
| 20 kg box, mixed pieces | Natural seiryu-style stone (calcareous) | Light-to-mid grey with white veining | Freshwater and marine safe |
Bioscape doesn't publish a piece count or individual piece dimensions for the box – it's a natural product and both vary between boxes. We're not printing a figure we can't confirm.
Suitable for, and not suitable for
Suitable for full-tank freshwater and marine aquascapes, and for terrariums, where a hard, mineral-rich stone is wanted to build a complete Iwagumi or mountain-ridge layout. Not a good match for soft, acidic setups – seiryu-type stone is calcareous and will gradually raise KH, GH and pH as it weathers, which makes it a poor choice for species that need soft water, such as many tetras, wild-caught shrimp and Apistogramma, or for plant-heavy layouts relying on low mineral content.
Preparation
Rinse the box thoroughly before use – a 20 kg box carries a lot of stone dust from handling and transport. Because it's calcareous, it's worth bucket-testing a piece first – leave it in a container of your tap or RO water for a few days and check KH, GH and pH before and after, so you know what to expect once the full build is in the display tank.
Warranty and delivery
Covered against being not as described under Australian Consumer Law. As a natural product, the pieces you receive will vary from the listing photo in shape, colour and exact weight – that's expected, not a fault. Sold and freighted as a 20 kg box.
Common questions
Will this raise my water hardness?
Yes, gradually. Seiryu-style stone is calcareous and slowly releases calcium carbonate, raising KH, GH and pH over time. Wash it well and bucket-test a piece first if you're running a soft-water tank.
Should I buy the box or the single piece?
The 20 kg box is sized for a full aquascape build – a complete Iwagumi layout or a large paludarium. The single-piece listing suits topping up an existing scape or picking one specific shape rather than committing to a full box.
Is it safe for shrimp?
It's not ideal for wild-caught or soft-water shrimp species, since the hardness rise it causes suits harder-water setups better than soft, acidic ones. Hardier, harder-water-tolerant shrimp are generally fine with it.
Will I get the exact pieces shown in the photo?
No – this is a 20 kg box of natural pieces, and the photo is representative of the stone type and colour range, not a guarantee of the specific pieces you'll receive.
