Various (Japanese bonsai brands) · Active aquasoil
Akadama (DIY Japanese clay)
Japan · Tan to reddish brown · grain 2 to 6 mm (sold by size grade)
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TL;DR, Akadama (DIY Japanese clay)
Akadama is a Japanese clay traditionally used in bonsai cultivation. Caridina shrimp tanks on a budget, or any planted tank where the keeper is comfortable buying from garden supply rather than aquarium retail.
Full specs
- Brand
- Various (Japanese bonsai brands)
- Country of origin
- Japan
- Category
- Active aquasoil
- Colour
- Tan to reddish brown
- Grain size
- 2 to 6 mm (sold by size grade)
- pH target
- 6.0 to 6.8
- pH effect
- Lowers (gentle)
- KH effect
- Lowers (gentle)
- Ammonia release
- Light
- Nutrient content
- Low
- Buffering longevity
- 18 to 36 months
- Recommended water
- RO preferred
- Difficulty
- 3 / 5
- Shrimp-safe
- Yes
- Best for
- Budget-conscious shrimp keepers, DIY substrate alternative
How it works
Akadama is a Japanese clay traditionally used in bonsai cultivation. The clay is processed into uniform granules with high cation exchange capacity, which lowers pH and KH similarly to manufactured aquasoils. The bonsai supply chain produces Akadama in much larger volumes than aquascaping demands, so the price per litre is much lower than purpose-built aquarium soils.
Best use cases
Caridina shrimp tanks on a budget, or any planted tank where the keeper is comfortable buying from garden supply rather than aquarium retail. Some experienced shrimp breeders prefer Akadama specifically for its low nutrient content because it forces them to dose minerals deliberately rather than relying on substrate leaching.
Common mistakes
Garden-grade Akadama sometimes contains pesticide residue or trace contaminants. Aquarium-safe sources need to be verified before use. The granules can crumble over time, especially if disturbed during planting; gentler grades (Akadama Premium, Double Red Line) hold up longer.
Pro tips
Hard Akadama (the "Double Red Line" grade) lasts significantly longer than the softer general-grade product. Akadama also pairs well with Kanuma (another Japanese bonsai clay) for tanks that want even softer water than Akadama alone produces.
Plants that thrive in this substrate
Hand-curated pairings based on the substrate category, not a relational query.
- Cryptocoryne WendtiiCryptocoryne wendtiiHeavy root feeder, thrives on the strong ammonia and nutrients leaching from new aquasoil.
- Amazon SwordEchinodorus grisebachiiBackground rosette with extensive root system, builds tall on the rich substrate.
- Rotala RotundifoliaRotala rotundifoliaStem plant that colours strongest under low pH + high nutrient soil conditions.
- Monte CarloMicranthemum tweedieiCarpeting plant that pearls quickly when rooted directly into aquasoil with CO2.
- Ludwigia 'Super Red'Ludwigia palustris 'Super Red'Reds deepen on active aquasoil thanks to the consistent micro-nutrient release.
Sources & further reading
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