Black, Fine Particle (~3mm) Fired Volcanic Ash Base Substrate


  • Natural volcanic ash with beneficial properties for aquatic plant growth and long-term care of fishes and motile invertebrates requiring slightly-acidic, low-GH water conditions.
  • Ideal for use as a substrate in shrimp biotope aquaria.
  • Binds elements that contribute to hardness, lowering GH and resulting in a slight
    acidification of alkaline water to a pH of less than 7.
  • Used as a primary substrate, forms the basis of a stable growth medium for rooted
    aquatic plants by:
    1. Permitting development of strong root systems.
    2. Encouraging nutrient-uptake through roots via increased interstitial water circulation
    (relative to higher-density substrata) and acidic pH environment.
    3. Allowing roots to remain sufficiently oxygenated to maintain plant health.



5 lbs. | 15 lbs. | 24 lbs.

Technical Background

In forested and low-relief riverine habitats, nutrient concentrations in the water column, itself, tend to be poor, the bulk of the nutrient pool existing within the substrate composing the river bottom; these nutrients are present primarily as a result of the continuous deposition of mineral- and organic-rich sediment being carried from upstream and from run-off. Water chemistry in such riverine habitats tends to be slightly- to moderately-acidic, and generally low in concentrations of the elements that contribute to general hardness ("GH"). Plants endemic to these habitats, which constitute the majority of species commonly maintained in planted aquaria, obtain a considerable percentage of their nutrient requirements through their roots; it is therefore sensible to utilize a growth medium in planted aquaria that facilitates delivery of nutrients to the roots, themselves, as doing so encourages strong root growth and long-term plant health. Maintaining plants, fishes, and motile invertebrates (such as the various species of shrimp that are maintained in biotope aquaria and as algal grazers) endemic to these habitats in water chemistry conditions, specifically in terms of pH and mineral content, similar to those that they have evolved in is also sensible, and is likely to have a positive impact on their collective health. FlorinVolcanīt Rio Escuro-F is a natural volcanic ash that has been formed into particles resembling oblong beads. The beads, themselves, are firm yet pliable, and are sufficiently durable to retain their shape for one or more years, depending upon the specific water chemistry in the system (a tendency towards alkaline water causes the material to deteriorate more rapidly than when maintained in water with lower initial alkalinity). Rio Escuro-F gradually lowers GH and pH to create conditions conducive to long-term husbandry of plants, fishes, and invertebrates endemic to most rainforest streams, rivers, and pools.

Instructions and Guidelines

In general, no rinsing of Rio Escuro-F prior to placement in a new aquarium system is required; because this is a natural material, it is possible that small pieces of wood may be present in the package. Consult an appropriate reference source for specific plant substrate depth requirements and proceed accordingly. Ensure that aquarium is clean and empty (addition to an aquarium filled with water will cause temporary cloudiness). Add Rio Escuro-F to desired substrate depth; if desired, the substrate can be sloped from front to back. Mineral sand can be used to enhance the appearance of the layout if desired. Prepare a sufficient volume of water (to fill the system) by adjusting to proper pH, alkalinity, and hardness values. Slowly (without unduly disturbing the substrate) add sufficient water to the aquarium to barely cover the substrate, then commence planting and when finished (again) slowly fill aquarium to desired depth with remaining water. Due to the semi-open structure of the substrate bed and the resultantly enhanced water diffusion properties throughout, it is possible to utilize liquid supplements and microbial suspensions, instead of particulate products, for maximum control of water chemistry and best results. The fastest means of inoculating the bed with beneficial microbes is to employ FlorinBacter per the recommended instructions. Other Florin supplements can be employed as required. With time, the neutralizing capacity of Rio Escuro-F will decrease and the substrate can be replaced at this time if desired. Use of alkaline buffers and pH-increasing substances will hasten deterioration of substrate. Do not use with undergravel filtration.


Caution: Keep out of reach of children; discard empty bag to prevent choking hazard.


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