A fine-to-medium grade of highly porous agricultural volcanic tuff. Depending on the application, it may also be read as a fine agricultural volcanic soil, engineered to build the medium, increase structural stability, and improve growing mixes with controlled moisture retention in the root zone.
The price shown is the retail price. Large-volume pricing varies by order size, packaging type, and destination.
This grade is the primary choice when the priority is medium building and moisture management within the active root zone.
All ratios are volumetric, not by weight. These are practical operating windows that can be adjusted according to crop, irrigation program, and water quality.
| Application | Recommended window | Technical reading |
|---|---|---|
| Peat moss or cocopeat mixes | 25–40% 0–4 mm + 60–75% suitable organic base | An excellent window for flowers, leafy vegetables, pots, and general nursery production. |
| Full mineral medium in grow bags or irrigated beds | 100% 0–4 mm, or 85–95% 0–4 mm + 5–15% 10–25 mm | 0–4 mm should remain the base, with the coarse grade added only as an aeration correction when needed. |
| Blending with compost | 10–20% mature compost + 20–35% 0–4 mm + the balance as a suitable base | Reduce the compost proportion if it is high in salinity or not fully mature. |
| Seedlings and propagation trays | Only 5–15% within a light propagation mix | It functions as a structural enhancer, not as a sole base. |
| Soil amendment | 5–10% by volume through a 15–20 cm depth, increasing to 10–15% in heavy soils or raised beds | The benefit comes from mixing it into the active root zone, not from limited surface scattering. |
Size selection remains tied to system design, medium depth, and irrigation or flood frequency.
0–4 mm functions as a stable medium base, either alone in highly controlled systems or within a balanced organic/mineral mix under precise irrigation with leachate monitoring.
It supports soil improvement in the active root zone and increases medium stability in light media, with clear benefits when it is truly mixed into depth.
It can work as a near-complete medium only in highly controlled systems, with a limited amount of the coarse grade added when the application requires more air.
It is useful when a less coarse medium with better moisture retention is needed, especially in shallow pockets and under precision irrigation.
Condensed placements derived from the comprehensive technical guide and the approved mixing windows.
Use 0–4 mm within the wetted zone or basin by actually mixing it into depth; it improves aeration and moisture management within the basin more than surface covering alone.
It serves this crop group very well at 25–35% within a suitable organic base, or as a near-complete fine medium in highly controlled mineral systems.
0–4 mm may work as a full medium under high irrigation control, or at roughly 20–30% within an organic base, because strawberry needs an aerated medium that does not dry too quickly.
It is recommended only at 5–15% within a light propagation mix, while the coarse grade is not used in small seedling trays.
Core validation files, technical cards, and operating documents.
It is not an absolute substitute for every application, but it works as a functional mineral component that increases stability and air while regulating moisture within the mix.
When you need a modest increase in aeration within a finer medium or a mineral system that is sensitive to drying. As a rule, 0–4 mm should remain the base.
Use only at 5–15% within a light propagation mix; it should not be relied upon alone as the sole medium in very small cells.
Yes, but only in some highly controlled systems, with tighter irrigation management and local testing of leachate and drying speed.
Share the crop type, cultivation system, medium depth, and irrigation program, and we will guide you to the most suitable positioning between the fine grade, the coarse grade, or a blend of both.
